spin-1/2-nuclei

Disclaimer: Sorry I'm just a chemist, so I'm not familiar with the procedures you've mentioned above. My research focuses mostly on the design and development of novel chemical reactions and we rely heavily on computational chemistry/molecular modeling so I spend about half of my time doing wet chemistry and the other half of my time doing computational chemistry. So, in short I am probably not the best person to help you with this, but since nobody else has come along yet, I thought I'd try to help. Hello, Based on what you're describing I think the chemist probably decided you'd only need 25 ml of solvent to dissolve your 500g of lipid and accomplish the rest of your tasks. As long as you're not currently having problems with your data I think it should be okay. hopefully this helps, but if it doesn't post again and I will see what else I can do to help. Hopefully an expert familiar with your field will come along. Best of luck with your research. Cheers

Before reading this post please see the definition of terms. This is how these terms are being used in the context of this post. 1. thermal energy - I am using the definition of thermal energy commonly employed when speaking about the temperature of a system that results from molecular movement. i.e. thermal energy = translational kinetic energy/random kinetic energy 2. Kinetic energy - the energy arising from molecular motion 3. average translational kinetic energy (sometimes interchanged with kinetic energy for brevity (see context of sentence to decide)) - the kinetic energy of the higher energy system that is being transferred - (via molecular collisions) - to another system of lower energy. Synonomous with thermal energy. 4. Random kinetic energy - see average translational kinetic energy. 5. Heat - the transfer of energy via translational kinetic energy - measured/described by temperature 6. Temperature = directly proportional to thermal energy/translational kinetic energy - the intensity of the energy NOT the amount. Temperature is directly proportional to the average kinetic energy. Thus, if you have two samples, and they are at the same temperature their average kinetic (random/translation) energy is the same. You are confusing the heat capacity (amount of heat required to change the temperature of the entire sample by 1 unit)/specific heat (the amount of energy required to change the temperature by 1 unit of one kg of the substance) - these depend on the amount of the substance as well as it's identity, etc, etc - with "thermal energy"... Which IS kinetic (translational/random) energy, because they (thermal/kinetic energy) refer to the intensity (i.e. the temperature) of the heat not the amount of it. That is to say, there is a difference between the amount of heat transfered/held (heat capacity/specific heat) I can transfer from one object to another and the intensity (kinetic/thermal energy) of the heat I am transferring. That is to say two suns in the universe might both be red giants (i.e. they have the same intensity (thermal/kinetic energy)) but if one can fit inside the other 20 times, then they will not have the same amount of heat (heat capacity/specific heat).. Thus, thermal energy/kinetic energy (rotational/random) in the context of heat transfer only measure the INTENSITY of the heat not the amount. This doesn't mean that temperature is not related to heat capacity/specific heat, but it does not arise from them. As I said in earlier posts, that is to say that temperature can be changed via many different external forces acting on the molecular system, but these external forces (whether or not they are directly or indirectly measurable) MUST change the average kinetic energy/thermal energy - if they are going to change the temperature. and as I said before, Energy taken into the system from an external source can either go to internal energies (such as bond making/breaking, etc) or it can be converted into kinetic energy, which is the motion of the molecules, which gives rise to the temperature. That is to say things like entropy don't cause the increase in temperature, but rather cause the increase in the kinetic energy of the system, which in turn cases an increase in the temperature. Two different sized pots of water will boil at the same temperature (intensity) - if all other factors in their environment are all the same - they DO NOT boil in the same length of time nor will they have the same amount of energy (specific heat/heat capacity). This is because you can look at the average kinetic energy of two identical substances in identical environments (regardless of their size) as constant and mostly identical value. That is to say you won't add heat to water on monday and get a vastly different thermal energy than you will on thursday, because water molecules use energy the same way in the same environment. So if we pretend that water's average kinetic energy increases per unit of Temperature is going to be 5 (imaginary energy units). Water when at 100C will be have an average kinetic energy/thermal energy/intensity whether it is 1ml or 50ml, i.e. the size of the sample does not matter. (this next part is overly simplistic - i.e. I am not calculating the energies but rather making them up - but it is an accurate mathematical representation of what happens all the same) So, if on average a water molecule's increase in energy (in isolation - I will deal with the environment of each individual particle next) is going to 5 per every unit of heat, then in my example above 5 molecules of water at 100 C will make the average kinetic energy (500 x 5)/5 = 500... now in the larger sample I have 20 molecules of water and they are boiling as well so I now have (20x500)/20 = 500 too. Now lets take those particles out of isolation and place them in real life. If we take note that - the kinetic energy of two identical substances in two identical environments will be the SAME - (otherwise I'm not sure what randomized kinetic energy would really do for us scientifically) - we can state that even though (due to environmental perturbations as no system is 100% uniform) the individual kinetic energies of a substance will vary within the system (that is why we say thermal energy/average kinetic energy is the average of the energies) if those particles are identical those energies will not - on average (not as the individual) vary extensively. Moreover, no matter what the size of the sample, as shown above, the intensity of the energies, remains the same. thus, 5 molecules of water @ 100C - molecule 1 = 500, molecule 2 = 500.000001, molecule 3 = 501, molecule 4 = 499.999999, molecule 5 = 500 you get (500+500.000001+501+499.99999+500)/5 = 500,19999 = the average kinetic energy/thermal energy in my imaginary energy units for this sample.. I never said there could be heat without energy transfer - ever. Again, the "confusion" is because you think the word describe can be somehow more closely defined as the word is in lieu of the word measure... I can't help you with that one because I intend to use the word describe as I have always used it, so why don't just agree to disagree. Moreover, in this case you are using the thermal energy of two different substances - if they have different chemical structures they will not have the same intensity/thermal energy/average kinetic energy in identical environments. That doesn't mean that you can't make one gas with a different chemical structure than another gas have the same intensity/thermal energy/kinetic energy [described/measured by temperature] in different environments. The fact that no heat is transfered also has nothing to do with the kinetic/thermal energy - only the - temperature. If/when that energy is ready/able to transfer the intensity will still be the same so long as the other parameters are kept constant. This is why nobody claims to know the amount of energy introduced into a system based on temperature (intensity) only. hopefully this clears it up. Cheers

^Yes, if you click on the link, the quote IS the definition of thermal energy, found under the section thermal energy. Cheers A better way to understand why kinetic (translational/random) energy is thermal energy is to ask yourself why a single molecule has no temperature? Temperature is in fact proportional to the average kinetic energy/thermal energy - i.e. - it is a measure/description of the intensity of the average kinetic/thermal energies. However we can say that each individual molecule has a kinetic energy - as I've said before. Hopefully this finally helps.. Cheers

No, I'm saying it's right because its right and that YOUR misinterpretation is both a) resulting from your confusion of the word describe As well as your now blantantly obvious misunderstanding on translational energy and thermal energy. They are not mutually exclusive - from your own preferred source read: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/rayj.html#c4 "The average translational kinetic energy possessed by free particles given by equipartition of energy is sometimes called the thermal energy per particle. It is also useful for comparisons of other types of energy possessed by a particle to that which it possesses simply as a result of its temperature." Thus my statement "temperature describes - i.e. - measures - the thermal energy which is the heat - i.e. - heat = translational kinetic energy = the energy being transferred IS accurate semantically according to your own preferred source. I'm sorry, but you're just wrong. I've spent a lot of time on this topic because I'm a scientist and I care about how science is presented to the world. Right now, you don't know what you are talking about and you are over complicating a very basic concept in introductory physics. That is to say, thermal energy is ONLY more complicated / "involved" in your mind and especially as it relates to this topic. Hopefully this helps. Cheers http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/eqpar.html#c1 Here is the correct link to the thermal energy tutorial from your preferred source. Cheers

@swansont.. Seriously? I know I said I wouldn't address this but I really can't resist. It's just ming boggling.. I didn't say heat = temperature... that association only happens in your mind. Which is puzzling since I later said that "heat is the transfer of energy from one object to another, and then went on to say an object of higher energy to an object of lower energy" WHAT I ACTUALLY SAID WAS.. temperature describes the average heat or thermal energy. NOT temperature is the average heat or thermal energy. "de·scribe (d-skrb) tr.v. de·scribed, de·scrib·ing, de·scribes 1. To give an account of in speech or writing. <----- is temperature not an account of the energy transfered from one object of higher energy to another of lower energy? (I guess you'd like to tell me what the unit of measurement we're currently using corresponds to or what the T is doing in PV=NkT. LOL! 2. To convey an idea or impression of; characterize: She described her childhood as a time of wonder and discovery. <--- I guess to you here she is literally saying that the word childhood (and all that implies) is a synonym for two complete different words, both wonder and discovery, thereby merging the individual definitions of all? 3. To represent pictorially; depict: Goya's etchings describe the horrors of war in grotesque detail. 4. To trace the form or outline of: describe a circle with a compass." - http://www.thefreedictionary.com/describes It's a shame... now we are also arguing about the semantics of the word describe, which obviously (if you read my post in it's entirety) is interchangeable with the word measure. All of this BS is just sad, because the person who started this thread really ONLY wants to know - HOW - does heat arise. Instead of explaining this to the poster you've decided to go out of your way to make ridiculous arguments about the semantics of the word temperature and heat, in isolation of the context of the posts where the terms were being used. This has resulted us now arguing about the semantics of the word described? Which if read in the full context of my post - obviously - meant measured - and if it wasn't clear to you that time - it SHOULD have been clear to you AFTER THE NUMEROUS POSTS I'VE MADE SINCE THEN.. YET, WE ARE STILL ARGUING ABOUT SEMANTICS.. WHY? sigh, what a colossal waste of time. LOL! You call this asking a question about science? My "ego" has no problem with questions or even different opinions, but my patience do have a problem with this: So basically what you are saying here is: a.) you haven't read everything I've said b.) you don't understand everything I've said yet c.) you're drawing conclusions about it anyway and d.) you thought it appropriate to take those conclusions all the way to he point where I don't know what I am talking about. You don't know me (or my qualifications for that matter), you haven't understood what I've said, and yet you are wasting my time by telling me I don't know what I am talking about without having bothered to read/understand everything I've said. Gotta say, that is disappointing, and in regards to your other question.. I already answered it in the numerous posts that you haven't taken the time to read/understand. Thus in lieu of a "rant" which I prefer to call a "desperate plea for people to be reasonable" - I think I will force myself to adhere to my original position and have nothing else to do with this thread. A normal discussion cannot be had like this.. Cheers

Apples and oranges.... 1. For starters the macroscopic level and the microscopic level are not the same. You can't shake your hand really fast and then say "see! there is no increase in temperature so kinetic energy does not increase temperature" - I mean - LOL! The environment determines how energy will be used and what it will be converted into. What many people fail to understand here is energy is energy and these arbitrary definitions of energy like (thermal/kinetic) are more to help visualize what is going on and less meant to actually outline a "different/better/worse" kind of energy. That being said, Even on the macroscopic level it is ridiculous to suggest that two identical objects - one moving and one at rest - will have the same temperature if their environments are identical accept for the speed at which they are traveling. If you want to prove to yourself why this is nonsense, even in laymen terms, do a thought experiment to test this out: take your hand a shake it wildly in the air (it will start to feel cooler), then take your hands and rub them together (it will start to feel warmer). In the first part, your hand cools down due to the loss of kinetic energy as a result of the work being done by the system (your hand) on the air molecules. So in this case the kinetic energy of the air molecules has increased, thus their temperature has increased while the kinetic energy of your hand has decreased since it was transfered to the air molecules in the form of heat and as a result your hand feels cooler while you are moving it wildly through the air. In the second part the kinetic energy of your hands being rubbed together is being converted - via friction - into thermal energy/heat - that is transfered back to your hands from one another and the work being done on the system is coming from the movement of your arms etc [so if we just consider the system of your two hands rubbing together and everything else as external energy sources it becomes easy to comprehend]. Thus I maintain that an increase in kinetic energy = an increase in temperature.. all day everyday.. hopefully this was helpful, but I'm checking out of this thread permanently since my tolerance for psuedoscience has been exceeded. You seem like a very smart and inquisitive person. I think you will have no trouble understanding these concepts if you crack open an undergrad engineering physics/calculus based physics text book. My honest suggesting is to avoid learning concepts based on information obtained from internet forums that degenerate into nonsense. If you don't have a solid understanding of the subject you will not be able to distinguish the valid scientific concepts, from the bs pushed by crackpots, and you might confuse valid concepts if they are wrapped up in semantics. So my advice is to find a naming convention that works the best for you to understand these concepts. The age old argument of heat energy vs. thermal energy doesn't really mean anything on the ground, and you can understand the concepts yourself if you take the time to get the information you're requesting from the right sources.. that's my two cents.. Best of luck with your studies Cheers

Hello, yes in the real world kinetic energy is responsible for the increase in temperature.. But, in this thread, I think the semantics argument is causing too much confusion, so this is what happens without the semantics: 1. molecules have movement and this movement results in an increase in energy, to avoid semantics let's call it E1 2. this energy - E1 - "stored" in molecules at high energy (i.e. high temp) is transfered to other molecules with lower energy (i.e. colder) via a process we will call "transference" 3. In this process called "transference" the E1 has a measurable energy ET (for energy of transfer to avoid using the term heat) that can be felt by you if you touch a higher energy object that has more energy than you and it's ET is transfered to you and the intensity of that transfer is measured by what we will call the "Ouch factor - to avoid using the term temperature). 4. This "Ouch factor" is separate from the ET although these things are all related as in the increase in one will increase the other and so on and so forth without - exceptional extenuating circumstances that are not found in the everyday - so we will ignore those for now just as airline pilots ignore combat maneuvers during their training for commercial flight. 5. Once the ET is fully transfered to other locations of lower energy - the "Ouch factor" you experience when touching all the objects in the system will be the same.. i.e. "ouch factor measured ETEQ - i.e. thermal equilibrium" will have been achieved. 6. BEFORE equilibrium is attained, ALL the sub-equilibriums inside each sub-system of the macrosystem must be satisfied. That is to say materials have pockets of lower and higher energy - as do molecules. It takes energy to rotate chemical bonds, and adopting certain configurations (without the making or breaking of covalent bonds) is a continuous process in the real word.. that is to say molecules are always moving. The movement - i.e. the E1 (which is kinetic energy in the real world) is derived from all of these different movements.. and this is how entropy - which I will call the "chaotic factor" here to avoid argument - is related to molecular movement. On the microscopic level there is a huge connection with the E1 (kinetic energy), "the chaotic factor" (Entropy), and the "ouch factor" (temperature) 7. So, once ET arrives at the other destinations it can be broken up into many different "types" of energy, which is just a way of saying the molecule that ET arrives at can use ET to either increase the molecular motions (E1/kinetic energy) which will increase the "ouch factor" as well as the intensity of the ET should it want to transfer it's energy to another molecule of lower energy in the form of "transference"/heat.. What happens to ET once it transfers from one molecule to another will depend on the environment. All systems strive to reach equilibrium - and so depending on what is best for the system the outcome of an ET transfer from one molecule in a system to another - or one object in the macroscale to another - will not be the same. That is to say transferring ET/heat from one object to another in the macroscale will not always have the same results. This is because objects are made out of different materials and different materials are made out of either different molecules - or in the cases of materials made out of the same molecules with different connectivity, different geometric configurations).. All this really means is that connecting atoms in different ways increase and decreases the rigidity in those molecular and supramolecular structures, which in turn results in differing intensities of E1/kinetic energy when ET/heat/thermal energy is applied to the system, which results in different "ouch factors" from the same intensity of ET/heat... ET can also be used to make or break chemical bonds (which depending on the situation will either reduce the "ouch factor" or increase the "ouch factor", etc. This is because E1 refers to all the movement in the system and chemical reactions can increase entropy "chaotic factor", which will result in an increase in the "ouch factor" which I described mathematically in another post.. and as I said earlier, molecular movement and entropy "chaotic factor" are very closely related, this is simply because maximum entropy "chaotic factor" is achieved when the molecules in the system are as evenly distributed as they can be - that is to say each molecule has the most space it can get - and that is just another way of saying the more space a molecule has the more degrees of freedom it has (remember when molecules get too close to each other repulsive forces and other attractive intermolecular forces act to lower the entropy "chaotic factor" of the system) - which is yet another way of saying (at the macroscopic level) stuff with more space to move without collision moves more. Thus, molecules with the same "E1"/kinetic energy will have the same "ET"/heat/thermal energy. Once "ET"/thermal energy leaves the high energy molecule A via "transference" and goes to lower energy molecule B and C, molecule B may or may not have the same resulting "E1"/kinetic energy. It will depend on the initial "E1"/kinetic energy of both B and C, their chemical composition, geometric configurations, and any other environmental parameters that interact with the system. The "chaotic factor"/entropy can be very different even between identical molecules depending on their environment - as explained above.. So, molecular motion produces an energy, that is then transfered to other molecules - of lower energy - in the form of another "type" of energy. The intensity of that other "type" of energy is proportional to the energy of the motion (even if that energy is not doing the same thing), and this is observed/measured by the intensity of the higher energy system in respect to the low energy system such that during the transfer of said energy ("ouch factor"/temperatureof the aforementioned energy will be proportional to the energy actually transferred. Which is not always the same as the energy that originated as systems - which in the real world do not exist in a vacuum - distribute energy as equally as possible throughout their sub-systems (from the perspective of what bring the system to the lowest possible energy, i.e. its most stable existence).. and you can think of this as many mini-equilibriums adding up to one macroequilibrium which describes the total energy of the entire system. Hopefully this helps.. Cheers

Wow JC, You'd rather insult me than actually back your position up with first principles. Your example is ridiculous. There is a difference between the macroscopic and microscopic level. Insulting me doesn't make the nonsense some people are pushing here any more accurate. Briefly, Yes a tennis ball traveling through the air at 95 mph has a different surface temperature than an identical tennis ball, which is sitting still. For many reasons, it's kinetic energy being one of them. A molecule moving at speed X, which is 10 times slower than the identical molecule moving at speed Y, will have a different temperature. Kinetic energy = molecular movement = temperature = a measure of the "hotness" i.e. heat transfer... I'm sorry that you guys seem unwilling/unable to understand this basic concept but this degenerated into a waste of my time a long time ago. Not to mention I personally find insults in stead of facts and logic a pointless way to have a discussion, unless of course one argues for the sake of arguing, which I do not. Thus if you guys want to believe that heat and kinetic energy are mutually exclusive - as in you can get one without the other- be my guest... I don't cater to bullies or egomaniacs. It takes time to learn these concepts beyond the basic high school introductory course. I'd suggest some people actually put in the effort to understanding kinetic energy, entropy (its relationship to the movement of molecules), temperature, and the concept of thermal energy as it relates to kinetic energy. ALL OTHER POSTS ADRESSED TO ME IN THIS THREAD WHICH ARE DEVOID OF VALID SCIENTIFIC QUESTION OR A VALID POINT WILL BE IGNORED.

I have to be honest I am really disappointed in this thread. I came here to answer a question about the definition of heat, which after further reading was clearly more of a request for information about how heat arises. In all the lengthy posts I've made on this topic, the only thing anyone really cares about are. a.) two statements taken out of context and b.) whether or not it is okay to make assumptions from statements found in posts - that were not read in their entirety - or if it was read in it's entirety - whether or not it is okay to make assumptions about statements that clearly contradict other statements made in the same post. This literally reminds me of kindergarden. I don't care about other people's assumptions and how they came about when I clearly stated the opposite in my post. I think that is fair. Moreover, I really don't want to talk about nonsense. To be quite frank, I've already learned this stuff and I am more than happy to discuss concepts, but when a difference in position has been firmly stated - as I did the previous post - and when I've made statements that directly contradict what I am accused of saying - in the same post the "offending" quoted statement is lifted from.. and then having to talk about those statements - despite clear context being given to those statements in numerous lengthy posts - leads me to the conclusion that right now the purpose of this discussion is not science. So, if you've read nothing else in this post please read: I don't want to discuss anything other than scientific concepts and I am more than happy to discuss different positions and perspectives, but I do not care to discuss semantics and preferences for information delivery (that is what questions and reading posts in their entirety to obtain context are for).. if you don't care enough about what I am saying to do one of those two things, then fair enough - but please don't waste my time by engaging me with responses to those posts. Seriously? It means that temperature is the measure of the average kinetic energy - which is the same as the thermal energy - and this thermal energy - i.e. heat (when being transfered) - i.e. the "hotness" is measured by temperature. "Kinetic energy is a general term describing the energy associated with the motion of objects (large or small objects). You can calculate the kinetic energy of an object of mass m with a velocity (speed) v from the formula K.E. = 1/2 mv^2. Thermal energy refers to the kinetic energy of the microscopic particles (atoms and molecules) that make up all samples of matter - i.e. all objects. When you add heat to an object, you increase the temperature of the object (usually) and that heat increases the kinetic energy of the molecules that comprise that object. In fact, temperature is a measure of the average kinetic energy of the microscopic particles that make up an object. Hope this helps.... Dr. Brown " - http://www.newton.dep.anl.gov/askasci/chem99/chem99045.htm "Heat is the total energy of molecular motion in a substance while temperature is a measure of the average energy of molecular motion in a substance. Heat energy depends on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object. Temperature does not depend on the size or type of object. For example, the temperature of a small cup of water might be the same as the temperature of a large tub of water, but the tub of water has more heat because it has more water and thus more total thermal energy." - http://coolcosmos.ipac.caltech.edu/cosmic_classroom/light_lessons/thermal/differ.html "kinetic - energy of motion potential - stored energy gravitational elastic chemical - energy of chemical bonds and reactions thermal - energy of heat - disorder" - http://www.uccs.edu/~tchriste/courses/PES100/100lectures/heat.html "Thermal energy is related to the temperature of matter. For a given material and mass, the higher the temperature, the greater its thermal energy. Heat transfer is a study of the exchange of thermal energy through a body or between bodies which occurs when there is a temperature difference. When two bodies are at different temperatures, thermal energy transfers from the one with higher temperature to the one with lower temperature. Heat always transfers from hot to cold." - http://www.tufts.edu/as/tampl/en43/lecture_notes/ch1.html So, from all of that we can conclude - as I have been saying.. heat is the transfer of energy from one object to another - it transfers from a place of higher energy (thermal/kinetic) to a place of lower energy (thermal/kinetic). From his own source: Thermal energy = "The average translational kinetic energy possessed by free particles given by equipartition of energy is sometimes called the thermal energy per particle. It is useful in making judgements about whether the internal energy possessed by a system of particles will be sufficient to cause other phenomena. It is also useful for comparisons of other types of energy possessed by a particle to that which it possesses simply as a result of its temperature." - http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/eqpar.html#c2 and "The kinetic temperature is the variable needed for subjects like heat transfer, because it is the translational kinetic energy which leads to energy transfer from a hot area (larger kinetic temperature, higher molecular speeds) to a cold area (lower molecular speeds) in direct collisional transfer." - http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kintem.html Thus, heat flows from hot (high thermal energy) to cold (low thermal energy) objects until they have the same thermal energy.... and we already know that thermal energy = kinetic energy when we are speaking about the motion of molecules [as I have been saying and saying].. "Microscopically, the thermal energy is the kinetic energy of a system's constituent particles, which may be atoms, molecules, electrons, or particles in plasmas. It originates from the individually random, or disordered, motion of particles in a large ensemble. The thermal energy is equally partitioned between all available quadratic degrees of freedom of the particles. These degrees of freedom may include pure translational motion in fluids, normal modes of vibrations, such as intermolecular vibrations or crystal lattice vibrations, or rotational states. In general, the availability of any such degrees of freedom is a function of the energy in the system, and therefore depends on the temperature." - http://en.wikipedia.org/wiki/Thermal_energy I disagree, I think other people might too, especially if they read everything I said. That is what context is for.. So, if for whatever reason you don't agree with what's been said above, please take that up with the sources (numerous university websites, etc) and not me. Cheers

It's a little distressing that you are ignoring integral parts of my previous posts. I never said two objects of the same temperature would have a transfer of heat.. in fact I said the exact opposite of that. Below is what I said. quoting me: Temperature describes the average heat or thermal energy (this implies of a system, i.e. it is clear when I go on to say). Thermal energy can be transferred by conduction (transfer of energy from one molecule to another), convection (movement of heat by a liquid or a gas), or radiation (transfer of heat by electromagnetic waves). and then I also say Thus "heat" is the transfer or flow of energy from one object to another. Or rather, one area of higher energy to one area of lower energy. So, in this very literal definition of heat, one can say that a single particle (if and only if it existed in isolation in the vacuum) cannot posses "heat", THAT DOES NOT MEAN THAT IT CANNOT POSSESS KINETIC ENERGY. To suggest that there is no correlation between kinetic energy and heat is a descent into ridiculousness that will result in a significant waste of the time you spend studying these concepts. The argument between the terms heat and temperature (while valid on a purely theoretical level) is really only saying that, because there would be nothing there to "observe" the heat - i.e. - the heat would not have anything to transfer to it would not exist. This in my opinion, while a useful academic point, is irrelevant when beginners are looking at the real world definitions of heat and what produces "heat" in molecules and other every day objects. and quoting me again: Heat is the transfer of energy from one object to another. Temperature describes the average heat or thermal energy (you've also said this). Thermal energy can be transferred by conduction (transfer of energy from one molecule to another), convection (movement of heat by a liquid or a gas), or radiation (transfer of heat by electromagnetic waves) ==================== So unless you are trying to say that all atoms or molecules in a system have the exact same temperature, temperature as I said before describes the average heat or thermal energy (of the system) as is implied (especially when reading the rest of my posts) That being said, I have no intention of getting in to a discussion about the definition of "heat" vs. "temperature". It's a ridiculous circular argument that detracts from the original points. My inflexible, and formal position on this issue is: heat is the transfer of energy from one object to another & only in the most ridiculous of situations does a discussion about the hotness (i.e. the temperature) of heat need to be undertaken to understand how molecular motion - i.e. - kinetic energy gives rise to temperature - which in turn gives rise to heat via the transfer of energy from one object to another as stated before. In the 19th century physics defined temperature as the measure of a system's kinetic energy: Now-a-days temperature is expressed as a relationship between the change in the internal energy, U, and the change in entropy, S, of a system. 1/T = dS/dU, but I already covered this in the chemistry thread earlier so I will just repost that here: again quoting me: So why then does kinetic stability decrease with increasing temperature? Well this becomes more apparent when we relate temperature to entropy. We can do so via T^-1 = (d/d(E))x(S(E)).. you can see that when temperature increases the entropy of the system also increases. ========= Thus, with an ideal gas as the internal energy increases the entropy increases. This is because the temperature is nearly always positive (unless we are talking about special conditions which arise in lasers, which we are not) Therefore, Unless you're planning to explain to me how heat can arise in any system without kinetic energy I'm not interested in debating the definitions of temperature or heat. Cheers and to get back on topic and answer this question for you since that should be the actual focus of this discussion.. There is such a thing called heat capacity: That is to say, when heat - i.e. - thermal energy - is introduced into a system it can be converted to either a.) kinetic energy b.) and other forms of internal energy that are specific to the material. This has a lot to do with the chemical composition of the material, it's geometric structure, etc. Whatever amount of heat is converted to kinetic energy will cause a rise in the temperature of that material. The heat that is introduced deltaQ, divided by the observed temperature change is the heat capacity of the material. Therefore, even the definition of heat capacity is not free from the use of the word temperature. We can even go so far as to talk about the specific heat of a substance, which basically is the amount of heat necessary to increase the temperature by one unit of measurement, whatever unit of measurement you're using.. I'm going to go with K for the hell of it.. either way we're still not escaping things like temperature and molecular motion (i.e. kinetic energy) when we talk about "heat". Nor, is the incorporation of concepts like temperature and kinetic energy somehow detracting from or in anyway stating that "heat" is anything but the measure of the transfer of thermal energy from one object (of higher energy - hot) to another object of (lower energy - cold). In this case "energy" refers to kinetic energy. When someone explains to you how they got heat to transfer from a "hot" object to a "cold" object - without utilizing temperature as the average measure of the kinetic energy to determine which of the objects was in fact hotter or colder then I will be all ears. so, At the end of the day if you want to know what heat is, I'd suggest you obtain a physics review article on the definition of temperature vs. heat, and decide for yourself. If you don't have access to Sci-Finder or the like try a good university library with graduate level physics books. When you read one of those sources you will find that the authors describe heat and temperature in the following ways: Statistical physics/mechanis describes temperature in terms of entropy, and it is a microscopic definition... Entropy describes the disorder of a system, that is to say entropy is the measure of the degrees of freedom of the system, and it increases as the logarithm of the number of different options the system has to organize itself, i.e. the number of degrees of freedom. Thermodynamics uses a macroscopic definition of temperature that correlates work and heat. In the most basic undergrad physics temperature is expressed in units of energy. For experiments conducted, in the real world (the ideal conditions obtained in the vacuum are so hard to come by in the lab), both the macroscopic and microscopic definitions of temperature are correlated via the Boltzmann constant (a proportionality factor that scales temperature to the microscopic average kinetic energy). So, as I have been saying and saying - temperature is a measure of the "hotness" of the heat which is a measure of thermal energy transfered from one object to another.. hopefully this was helpful, Cheers

Wow, balantis. That's unfortunate, damn... Gotta say, I read this and at first I was like not gonna respond to that, but then I figured if you're asking about this on a chem forum you are either pranking, lost, or desperate.. In any case my ego can take it if your pranking, and if you're lost or desperate well, I can at least point you in the right direction. sigh... All of the information below assumes that you have seen or are planning to see a doctor: 1st. I would suggest visiting one of those medical forums where real doctors will often respond to your questions. I'm just a chemist, so that is not going to be overly useful to you at this time. 2nd. Before or after you do that, go to this link: http://www.nhs.uk/Conditions/Balanitis/Pages/Treatment.aspx It's reputable (the NHS), i.e., none of that homeopathic do it yourself at home with random herbs bs.. The Since you might be looking for alternative treatments... As a chemist, the only thing I can tell you is don't. If it isn't sanctioned by your doctor stay away from it. If you don't like your doctor you can always get a second opinion from a different one... There's literally no regulation on "natural" dietary supplements that claim to heal this, grow back that, or reverse this. Avoid them, unless you like to waste your money on mineral surprise. The quality assurance, components, and concentrations for those things are not regulated by the FDA. Moreover, there are just as many crackpot doctors as there are bottles of contaminated, low quality, health damaging crap in your local GNC, avoid the crackpot doctors too. They either bought their MDs online or found them stuffed inside a children's cereal box.. Best of luck, Cheers

For what it's worth you are right, both academically and in normal everyday real world situations. The moment someone explains "heat" without mentioning kinetic energy or molecular motion, they will have won a Nobel prize, because it will change the way we view thermodynamics. You cannot separate the concept of heat from the concept of molecular motion and kinetic energy. As I said in an earlier post: Heat is the transfer of energy from one object to another. Temperature describes the average heat or thermal energy (you've also said this). Thermal energy can be transferred by conduction (transfer of energy from one molecule to another), convection (movement of heat by a liquid or a gas), or radiation (transfer of heat by electromagnetic waves) Thus in the land of endless arguing for the sake of arguing - where people wonder if Schrodinger's cat is really dead/alive inside that box - perhaps he is just sleeping? - and whether or not the world around them is in fact filled with other autonomous humans - (could all be a figment of their imaginations?)... the forest is lost through the trees, since to most people trying to understand this (who aren't going forth to get PhD's in particle physics and even most situations for people like me getting PhDs) a literal definition of heat is virtually useless.. As I said before, one can say that a single particle (if and only if it existed in isolation in the vacuum) cannot posses "heat", THAT DOES NOT MEAN THAT IT CANNOT POSSESS KINETIC ENERGY. I'm really impressed with how much you've taught yourself. Best of luck with the rest of your studies (be they at uni or for your own amusement). Cheers

Hello, The poster whom you addressed this question to is correct. If the average kinetic energies of the gasses are the same then their temperatures will be the same. The real question you should be asking here is what impact will container size have on the pressure and what effect will that have on the kinetic energy of the gasses? From the kinetic theory of gases: gasses are made up of molecules where the system energy has surpassed the energy of the intermolecular attractive forces. Molecules in the gas phase are constantly moving (i.e. they have kinetic energy). This movement results in collisions with other gas molecules and in the case of a gas inside a container the walls of the container as well. The relevant physical properties are mass, momentum, and energy.. noting that kinetic energy increases as both temperature and mass increase. The momentum of an individual gas molecule = mass (times) velocity. The kinetic energy is 1/2mass (times) the square of the velocity. When the gasses collide with the container a force perpendicular to the wall is exerted. Pressure is equal to the sum of the forces striking the container wall divided by the area of the wall. So the pressure of a gas is thus a measure of the average linear momentum of the moving gas molecules. Thus, if you increase the pressure of your container (by reducing it's size but keeping the number of gas molecules constant as well as their kinetic energy) you will increase the temperature, which will in turn increase the kinetic energy - therefore they cannot be the same. Volume will increase in a container whose pressure has increased assuming that the walls of said container are flexible. If they aren't and you change the volume of the system it will either explode or implode depending on the circumstances. getting back to the question of "what is heat?": Heat is a measurement of energy. The hotter an object is, the faster the motion of the molecules in that object. Therefore "heat" is the TOTAL energy of all of the molecular motions in your system. Temperature describes the average heat or thermal energy. Thermal energy can be transferred by conduction (transfer of energy from one molecule to another), convection (movement of heat by a liquid or a gas), or radiation (transfer of heat by electromagnetic waves). Thus "heat" is the transfer or flow of energy from one object to another. Or rather, one area of higher energy to one area of lower energy. So, in this very literal definition of heat, one can say that a single particle (if and only if it existed in isolation in the vacuum) cannot posses "heat", THAT DOES NOT MEAN THAT IT CANNOT POSSESS KINETIC ENERGY. To suggest that there is no correlation between kinetic energy and heat is a descent into ridiculousness that will result in a significant waste of the time you spend studying these concepts. The argument between the terms heat and temperature (while valid on a purely theoretical level) is really only saying that, because there would be nothing there to "observe" the heat - i.e. - the heat would not have anything to transfer to it would not exist. This in my opinion, while a useful academic point, is irrelevant when beginners are looking at the real world definitions of heat and what produces "heat" in molecules and other every day objects. So, unless we want to needlessly create paradoxical situations by descending into the metaphysical arguments of Schrodinger's cat and the like, it is perfectly reasonable to say that kinetic energy is a result of molecular motion which increases the temperature which in turn increases the "hotness" of the object which is in fact observable in the form of heat and heat is in fact just a measure of the energy (that makes things hot) being transfered from one system to another. A good way to prove this to yourself is to ask someone to try to explain the concept of heat to you without mentioning anything about temperature or molecular motion/kinetic energy. Hope this was helpful, Cheers This is correct. Heat is not really a thing - it is a measure of a thing - and that thing is energy. You're on the right track here, but just a few pointers, if you don't mind. The kinetic energy of the gas molecules increasing or decreasing as a result of the external environment will not make the gasses into different gases. A chemical reaction has to take place in order to break bonds, and you must break chemical bonds in covalently bound structures to obtain a different substance. An increase in kinetic energy won't move the molecule into another energy level (as in it won't convert the electronic configurations of the molecule's atoms into other atoms), but rather it increases the molecular motions. So collisions, bond rotations, etc will be faster. Kinetic energy has a direct effect on the physical properties of molecules though. An example of this is, Water in the solid form (ice) has different kinetic energy than water in the liquid form. This is because in the liquid form water molecules can more easily move across each other. This is because they have more kinetic energy, and while they are still water molecules in the gas phase, they have even more kinetic energy resulting in the phase change. Hopefully this was helpful, Cheers

Hello, This will be a long post: the kinetic energy of a particle describes the work required to accelerate/decelerate an object from rest/motion to it's current velocity. You're not that off tract - i.e. there is a relationship between temperature and kinetics and it comes in the form of particle/molecular motion and entropy. In chemistry the temperature of a molecule is the measure of the speed at which the particles/molecules are moving - thus it is a measure of their kinetic energy. Increasing temperature increases molecular movement, therefore, increasing temperature increases kinetic energy. In chemical reactions: The time it takes a reaction to occur is the measure of it's kinetic stability. So the faster it reacts the less kinetically stable it is. Thus products that are kinetically stable are sometimes incorrectly said to be unreactive when in reality they need energy to increase the rate at which they react. Moreover, people often confuse kinetic and thermodynamic stability. In short, the kinetics control both the rate and the pathway of the reaction, the thermodynamics focus on the energy differences between the products and the reactants. In thermodynamics you have - Enthalpy If a reaction takes in heat (i.e. if heat is required to move the reaction forward) - it is said to be endothermic. If the reaction gives off heat (i.e. if heat is produced during the reaction) - it is said to be exothermic. Whether or not a reaction will give off heat or require heat is related to the bond dissociation energy. This can be quantified by the enthalpy (H) of reactions. The deltaH = H-products - H-reactants. So, to put endo/exothermic reactions another way.. If you have a positive deltaH then you have an endothermic reaction. If you have a negative deltaH then you have an exothermic reaction. Moreover, if the products have a greater total bond energy than the reactants the reaction is exothermic if the products have a smaller total bond energy than the reactants then the reaction is endothermic *note, that bond energy is NOT an innate energy source for molecules - i.e. - it is not part of the molecules potential energy, but rather has to be introduced into the system from a third party source. Activation Energy - is the energy barrier that the reactants have to overcome to begin the process of conversion to products. It's important to note that exothermic reactions - are just as susceptible to activation energy as endothermic reactions - i.e. most exothermic reactions do not proceed spontaneously. and this is how heat is related to kinetics in a chemical reaction: The energy (in the form of heat) - activation enthalpy deltaH(double dagger) that is required to bring the reactants to the activation enthalpy - is for the most part inversely proportional to the reaction rate and is highly dependent on the concentrations of the reactants. Thus, as far as stability goes: thermodynamic stability can be described as the enthalpy or potential energy (this is an over simplification but works at the qualitative level - for more info look at the Gibbs free energy function - deltaG) when compared to some standard. For exothermic reactions the products are thermodynamically more stable than the reactants. For endothermic reactions the reactants are more thermodynamically stable than the products. In Gibbs free energy, entropy (deltaS) is incorporated and you have what are called endergonic and exergonic reactions. Endergonic reactions have a positive deltaG and require external input from the environment into the system in contrast exergonic reactions have a negative deltaG and often occur spontaneously. In cases where deltaS (entropy change) is small deltaH = deltaG, but in cases where entropy change is large that is not what happens. Looking at the equation below, you can see that the significance of deltaS increases with increasing temperature. deltaG = deltaH -TdeltaS which is another way of saying: free energy = enthalpy - (temperature)x(entropy) there is also a free energy of activation - which incorporates entropy as well, and explains why NOT ALL exergonic reactions are spontaneous. Thermodynamically speaking - entropy relates to the order/disorder of a system. Mathematically, you can think of it simplistically as a description of all the energetically relevant degrees of freedom available for the system. In atoms and molecules the more molecular movement possible (bond rotations, etc) the greater the entropy, the same is true for the mass.. the greater the mass the greater the entropy. Since I already stated earlier that kinetics deals with the movement of molecules which is just another way to define the temperature you can see now how kinetics relate to temperature and chemical stability. So why then does kinetic stability decrease with increasing temperature? Well this becomes more apparent when we relate temperature to entropy. We can do so via T^-1 = (d/d(E))x(S(E)).. you can see that when temperature increases the entropy of the system also increases. So, if you look at kinetic stability - the molecules that are the MOST kinetically stable - react very slowly and in some cases do not react at all. So increasing the kinetic energy of a system, increases the temperature, which in turn increases the entropy, and makes kinetic control of the reaction less likely as temperature increases. For example. If we have reactants A&B that are kinetically stable, but are thermodynamically unstable (i.e. once they react they will react exothermically) depending on the reaction conditions (thermodynamic vs kinetic) control you will get two different results. The activation energy for the reaction that leads to the thermodynamic product will be higher than the activation energy for the reaction that leads to the kinetic product. So in this way it is somewhat confusing to say that the reaction temperature is lowered to provide the kinetic product. That reaction temperature typically only corresponds to the thermodynamic product, which in fact has a higher energy of activation, so from the perspective of the kinetic product the temperature has not been lowered, and has in fact been raised to a point that is sufficient to over come the kinetically stable molecule while at the same time not exceeding the energy required to reach the activation energy for the thermodynamic product. It is also confusing to speak about kinetic energy when speaking about kinetic stability, because every activation energy for every reaction is relevant to the kinetic energy of the reactants, that is to say - all chemical reactions have activation energies and all molecules have kinetic energy. So if you are working with reaction conditions that are specified for the thermodynamic product and you want the kinetic product you will lower the temperature. If, however, you are starting from scratch with your own procedure and you want to obtain the kinetic product from kinetically stable reactants you will have to raise the temperature to increase the kinetic energy of the reactants. Hope this was helpful, Cheers

Hello, Sorry, this post is going to be long: Regarding de-excitation.. the quick answer is - it depends on the environment. That is to say not all photos and electrons are created equal. That being said: Electrons which have "vibrational energy" - i.e. they can vibrate without colliding with other atoms undergo both excitation and de-excitation. I've explained why excitation occurs in more detail in the previous post - but quickly - when an electron absorbs a photon excitation occurs. Once that happens the electron is now occupying a more UNSTABLE energy level. This means that the electron will not want to remain "there" - because this has a destablizing effect on the entire system to which it belongs - i.e. - all systems universally try to attain the lowest energy possible, that is to say - all systems are trying to achieve maximum stability. Moreover equilibrium isn't a process reserved just for chemical reactions, so not all pathways to the lowest energy "configuration" are created equal for all systems. To go more in depth: In thermal equilibrium the energy density ρ(ν) of photons with frequency ν is - at least in most examples - constant with respect to time - that is to say that the rate of absorption = the rate of emission. Thus, in the Einstein model the rate of transition from a lower energy level to a higher energy level is proportional to the # of atoms with energy at that lower energy level & the amount of photons with that frequency - i.e. the energy density. So, for de-excitation - i.e. emission, there are 2 options. 1. spontaneous emission - in spontaneous emission the atom in the higher energy state decays to the lower energy state via the *spontaneous* emission of a photon.. The photon released had the energy equal to the difference in energy between the high energy and low energy levels, but in this case both the phase and the direction of the photon are random. phase = in waves is the fraction of a wave cycle which has elapsed relative to an arbitrary point. [the relative to the arbitrary point will be important later] To describe this, quantum mechanics has to be extended (because traditionally atomic levels are quantized but electromagnetic fields are not) So, we need what is called quantum field theory to explain all of this. In quantum field theory the electromagnetic field is quantized at all points in space. I will get to this more later, but for now, you can think of it like this for a *qualitative view* - the decision to leave is made by the entire system if you will, because systems do whatever is best for the system as a whole (as a sum of whatever is best for all the sub-systems in the macrosystem) to attain maximum stability. 2. Stimulated emission - comes from interacting with an electromagnetic wave of the appropriate frequency, etc. Photos emitted in this way will have the same phase, polarization, frequency, and direction when they are emitted as they did when they were absorbed. Now there is no standard pathway to de-excitation for all electrons because in reality things do not exist in a vacuum... Photons are qualitatively speaking - "balls" of radiant energy - and are basically the particle form of light. The amount of energy a photon has is calculated via E=hf, where f is the frequency of the light wave and h is 6.64x10-34j sec (Planck's constant). The energy of the photon that is released during de-excitation exactly matches the difference between the initial energy state of the electron and the electron energy states, i.e. no energy is lost. Moreover, not all interactions are created equal. The relationship between the energy state of the photon and the fundamental energy states of the atom will greatly determine how many interactions take place. That is why for example, photons travel at different speeds through different mediums. Since no energy is lost or gained the photon exits with the frequency it entered with, however the travel time - i.e. the speed of the photon - has been altered. You can also look at this from the perspective of the atom - i.e. - orbital energies are unique for each atom of a different element. sigh... All of that being said: In spontaneous emission the stationary state of the atom no longer meets the definition of a true eigenstate describing the co-system of the atom and the electromagnetic field. Most notably, when the electron moves from the excited state to the electronic ground state, these states mix with movement of the electromagnetic field from the ground state (the vacuum) to it's excited state (a single photon field state). Thus, spontaneous emission in free space cannot occur without disturbances in the vacuum. Moreover, despite having only one electronic transition between the excited and ground state of the magnetic field mapping the process is not that straight forward because there are many mechanistic pathways the electromagnetic field can take when moving from the ground state to the excited state and back. Basically, with respect to the trajectories along which the photon can emitted the EM field has many many many more degrees of freedom than the atom - i.e. the EM's phase space is > the atoms. Which is where the concept of electronic excitation and photonic excitation comes in to play - i.e. - the atom decays via spontaneous emission as a requirement of the system parameters. Which is basically saying that time spent in the excited state depends on the light source and the environment, as mentioned earlier in this insanely long post. So, what does all this have to do with the uncertainty principle? The uncertainty principle doesn't explain the how of spontaneous emission so much as the why it is difficult to empirically observe in the lab. Basically, de Broglie suggested that - just like light - electrons and protons will have both particle and wave characteristics. That is to say that the behavior of electrons can be treated like wave functions. If we are looking at electrons in either their wave or particle form, the uncertainty principle basically states that the more we know about the current position of a particle in quantum mechanics the less we know about it's future momentum. In the case of wave functions: wave systems have non-zero amplitude - i.e. - their positions are unknown. You have to compress the waves to accurately obtain their position. The momentum is proportional the wavenumber of ONLY one, but, ANY one of the waves in the system/packet - i.e. - the more you know about the momentum the less you know about the position and the reverse is also true. So the uncertainty principle deals more with how we quantify quantum particles and less with how/why they actually behave the way they do. I like to think of the uncertainty principle as one of the bridges (albeit imperfect) connecting the actual reality of the universe with our observable reality. Sorry, I didn't have as much time as I needed go into anymore detail.. my carbon is done so I have to return to the lab.. If you want more information on this I would suggest hitting up Sci-Finder and getting some review articles on photon emission. Hopefully this helps, Best of luck with your studies.. Cheers

Hello the kinetic molecular theory of matter can explain this. The following is not all inclusive but: Basically atoms and molecules move, and although we cannot observe this motion it gives rise to the different states of matter. The energy of these movements corresponds to the temperature of the substance. The higher the energy the more movement you will have. Moreover, the amount of energy atoms and molecules have determines how they interact with other molecules and atoms and with themselves. At the atomic level, the subatomic particles play an important role in determining how hard/soft and atom is, how it will bond, and the geometries those bonds can adopt. At the molecular level, things like sterics (the size of the bond), hybridization (the number of bonds between two neighboring atoms), intermolecular forces (hydrogen bonds, van der waals, pi-stacking, etc), and other things like the identity of neighboring atoms (i.e. functional groups) in a molecule, and their connectivity (which determine pockets of electron density and deficiency), conjugated systems, pockets of rigidity, the list goes on and all of these things working together determine the physical and chemical properties of molecules like water. Atoms with lower energy move less, thus they tend to be solids, whereas Atoms with high energies have a lot of movement and thus they typically form gasses, thus liquids are somewhere in between. This explains why freezing water turns it into a solid... the lowering of the temperature lowers the movement and therefore results in the formation of a solid (ice). Put another way, when the attractive forces between individual molecules are > the repulsive forces you get a solid. These solids are still moving (i.e. they have NOT obtained absolute zero - the temp at which all movement stops), there movement has just been restricted to vibrational movement. In liquids like water, the intermolecular forces - such as hydrogen bonds - allow the molecules to move past one another but do not allow them to gain sufficient distance from one another to fully disperse and escape the intermolecular attractive forces. When you have a gas the energy of the system is > all the attractive forces thus the individual gas molecules expand out as far as they can get from one another unless/until external factors are present. hope this was helpful Cheers

Hello, First some background on this kind of titration: In Redox reactions you have an oxidizing agent and a reducing agent. Oxidation = loss of an electron(s) Reduction = gain in electron(s) Therefore the oxidizing agent will be the one that accepts the electrons & the reducing agent loses them. These reactions (oxidation & reduction) take place at the same time. Some important things to note: There must be a considerably difference between the strength of the oxidizing agent and the strength of the reducing agent for good results. You use the standard reduction potential SRP to predict what will be oxidized and what will be reduced in a redox reaction. The SRP basically measures the ability of reagents to gain or lose electrons. The more positive the SRP the more it likes electrons the > the potential is to be reduced. Now to help you answer your question: The strength of the oxidizing agent is heavily dependent on the PH of the solution. So, the more acidic or basic the solution is the stronger the oxidizing agent. Accordingly, as the PH of the solution approaches neutral the ability of the oxidizing agent decreases significantly. Also remember that permanganate is self indicating and cannot be used as a primary standard: note that this is due to the impurities found in permanganate solution and the fact that it is so good at what it does. Thus it is a secondary standard that must be titrated against a primary standard. So, to answer your question: a.) Redox reactions work better in acidic or basic medium and their strength tends to decrease in neutral environments. Moreover, permanganate works in all three, but in the particular case of permanganate (it works best under acidic conditions) - I will explain why below. b.) The aqueous solutions of permanganate are typically not stable for long. In addition, the permanganate typically comes contaminated with trace amounts of manganese dioxide (catalyzes spontaneous decomp of permanganate) and organic matter. When these organic substances react (catalyzed by light) with permanganate, MnO2 crashes out of solution. The permanganate also decomposes when exposed to manangous ions, however, that reaction is slower in acidic medium. Hope this helps Cheers

Those all sound like good schools. The University of Iowa was devastated by a major flood a few years ago so make sure you check the area and talk to the professors to be sure all the university facilities you will need for your PhD are up and running before you apply. The best way to determine which professors are taking students is to contact the departments you are interested in and go from there. Sometimes the secretary will have this information for you... You can also contact the professors themselves but you want to be careful about bombarding professors with emails... typically if they are not near retiring or going on sabbatical then they will likely be taking new students... good luck with your search for a grad program... the best place to start to answer all of your questions is the department you want to attend. You should pick the grad school first by the research and second by the location... that's my two-cents.

Don't we all.

This is very true. I decided to go for a PhD because I love the research that I do knowing full well knowledge and better understanding might be the only thing I obtained from the degree. @ the OP: You should really read over what CharonY has said. Chances are you will NOT get a tenure track faculty position, it is also likely that you won't end up working in your field at all. I don't think anyone is saying that "it's hard so don't try" I think what is being said here is that "it's hard so don't try it unless you love it and are well aware of the possible negative outcomes". Would the experience still have been worth it to you to gain the knowledge and understanding if you don't end up working in your field? If the answer to that is no, then you should reconsider undertaking the difficult and sometimes thankless task of earning a PhD. You will probably be able to find a job, so it isn't as if you will be totally unemployable with a PhD, but you just can't have that as your only motivation to start the process or you will get 2 years into it, hear about the horror stories of fellow PhD students/graduates and likely switch to some other field. Good luck. hopefully all works out for you.

^ Hi, if you are going for the master's in education you will probably need financial aid. You can pursue a PhD without needing separate funding if you ace the GRE general and a subject exam you will qualify for fellowships if none are available or the competition is very steep then you will definitely qualify for a teaching assistantship. At most decent schools that will cover all of your tuition, provide health insurance, and pay a stipend of at least 20 to 25k a year. To be honest with you, the master's in education is not going to help you much if you are looking for a PhD in neuroscience. There isn't much overlap in the course work. The admissions committee won't care if you can handle any graduate courses they are going to care specifically about graduate courses that are related to your science. I would suggest talking to someone at your university about enrolling in graduate courses in either biology, biochemistry, chemistry, or psychology. All of those are related to neuroscience. You might be able to pursue a psyche.D which isn't a doctorate of philosophy and beyond that go for a PhD in neuroscience at a later time if you're worried that you won't get accepted anywhere. I would suggest calling the graduate admissions offices of the schools you would like to apply to for neuroscience. I suggest picking 10 schools. 3 really good ones 5 middle schools and 2 bottom schools. Get in contact with the neuroscience department's graduate secretary and ask if it is possible for you to speak to either the director of graduate studies for the department you want to join, director of graduate admissions, or their graduate coordinator. Explain your situation to them and ask them if taking some graduate courses in a related area and doing a year of research will help over come your lower science GPA. Explain the reason why you have the low GPA and go from there. If all of that looks like it won't lead to anything useful, then I would consider a PhD in biology, next a PhD in biochemistry, followed by a psyche.D, then a PhD in education, after that I would consider the master's in education. hopefully this was useful. Your GPA is important but it isn't everything. Study up for the GRE if you haven't taken them already and make sure you ace the general (near perfect score) and make sure you ace a subject test (the biochemistry test is very difficult so be sure to study) - that alone should overcome your low GPA and lack of research experience even without taking the graduate courses but it will be extremely hard work. If you combine that with 6 to 9 credits of As in biology, chemistry, biochemistry, or psychology related graduate level course you WILL get into a top 10 school. You can avoid the physics and still get (I know what the admission sites say but ignore that). If you ace the calculus they will overlook the physics and you can tell them you did not have the time to take both in your personal statement if your undergraduate advisor feels you need to address the issue of having no undergrad physics. hopefully this helps. Good luck. edit: oops this is directed at the OP.

To the OP: What you could do is complete all of the requirements for your BS and hold off on graduating for a year. During that time you can petition the department to take graduate level classes before you go to graduate school a semester or two of this will do you a lot of good. The ideal number is about 9 credits if you are trying to overcome a really low GPA in the sciences, but the more the better. You can also take the physics and math while you're doing this. You WILL definitely get an undergrad research slot if you've done well in some related graduate courses. If you don't have access to research in your chosen area, then the next best thing to do is try some research in a related field (the harder the better). If you can get some research in the are of biology, chemistry, math, or physics and prove you can do science it will be better than no research experience at all. Good luck, and if you need any further advice and feel I can be of some help to you feel free to PM me. I'm sure if you stick to it you'll do fine and if you want the PhD go for the PhD... also if you'd like I can give you some tips on writing a good personal statement. If your grades were bad because of illness and not because of being lazy or unable to perform the work then you can simply state that in the letter - getting letters of rec from your undergraduate advisor or some professors that might also be able to back this up would be a huge asset. In my case my science GPA was really high when I left undergrad, but I took a lot of graduate classes and after I was accepted into an extremely good PhD program they told me they wouldn't have cared if my undergrad GPA hadn't been so good. I took over 20 credits of grad science courses during undergrad and got nearly a 4.0 in them... most of the people on the admissions committee had no idea what my grades were in the rest of the courses for my undergrad. So, I'm not saying it will be easy, but it will give you an option. You could get a coursework master's during this process as well but it probably won't take more than 9 credits of As in grad classes to overcome your low GPA... good luck.

Yes you are right, the pka of the amide proton is 8.3 - so the first step is the deprotonation of the phthalimide hydrogen, and next the nitrogen anion attacks Bromine, and then attack of either of the carbonyls by hydroxide and then you will get to the same intermediate, you will still have to do the intramolecular proton transfer to avoid the carboxyllic acid formation... and then the rest of the mechanism should be the same... hopefully this helps.

Hi please correct me if I am wrong, but I think you are asking how to understand stereochemistry and reaction mechanisms in organic chemistry. I'm probably not going to be able to give you a complete response, but I will do my best to point you in the right direction. First I will start with mechanisms because once you understand those, it is easier to talk about stereochemistry. Before you attempt to write a mechanism in chemistry you need to understand the following concepts. (This is not all inclusive, but should get you going in the right direction) 1. electronic ground state configuration for the atoms and how to assign this 2. understand formal charges and how to compute the # valence electrons 3. hybridization 4. resonance structures 5. sources of electron density and deficiency (nucleophile vs electrophile) 6. HSAB(hard soft acid base) theory 7. pka(s) of the common functional groups 8. leaving group stability 9. solvent 10. Know if a step in your mechanism is reversible or not 11. be aware of any possible competing reaction pathways Once you have all of that information, the first thing you do is identify the functional group on your molecule that is the most reactive for the particular type of reaction and the conditions. (i.e. SN1, or rearrangement reaction, or acid base reaction etc). Next you make sure to move electrons towards a source of electron deficiency and be mindful of octets, make sure to place negative charges on the most electronegative atom and positive charges on the least, also be sure to pay attention to the pka(s) of acids and bases remembering that equilibrium lies in the direction of the weakest acid. We can try a few mechanisms if you'd like: Here are a couple of questions you can do if you want and I will check out your answers and walk you thought them if you've made any mistakes. 1. Fischer Esterification of Benzoic acid with H2SO4 and excess ethanol. 2. Aldol condensation of Acetophenone and benzaldehyde 3. T-butyl chloride with phenoxide (will this be an SN1, SN2, E1, or E2? Why?) In order to understand stereochemistry you must have a good understanding of spatial orientation. There is no way to explain all of stereochemistry in one post, but I can point you in the right direction. Be sure to be very familiar with the following concepts. 1. enantiomer 2. diasteriomer 3. mesocompound 4. isomer 5. R & S 6. relative vs absolute stereochemistry 7. Re face vs Si face 8. chirality & prochiral centers 9. molecular symmetry 10. racemic 11. %ee and %de (enantiomeric and disateriomeric excess) I can't tell from your post what your level of exposure is to stereochemistry, but if you're looking for practice problems let me know and I can PM you links to some good websites with some of these. hopefully this was useful to you.

Hi I'm not sure if I completely understand what you're asking but it sounds like the FAB might not be ionizing your compound. Another possibility(which is less likely) is there is a problem with your instrument. Do you have any other ionization techniques available to you? You might want to ask the technician to run an EI with the highest eV. hopefully this helps if not let me know more about what you expected your compound to be and maybe I can offer some other suggestions. Good luck.