Chemistry

Help In my chemistry text it says that '2Cl represents 2 atoms of Chlorine' But 1mol of Cl has 6.02x10^23 atoms How could 2Cl only represent only 2 atoms? Tnx

I have been reading in my chemistry book about oxidation numbers. For the elements that have several oxidation numbers, how can you predict which one it will use? I know it has something to do with the difference of the electronegitivities between the elements, for example: Since Nitrogen has a higher electronegitivity than hydrogen, the nitrogen atom will gain a negitive oxidation number and the hydrogen will gain a positive oxidation number. Since the electronegitivities are far enough apart, nitrogen can assume its highest negitive oxidation number, which happens to be -3. So in order for the sum of the oxidation numbers of the elements to equal zero, there must b…

[math]k=Ae^{\frac{-E_a}{RT}} [/math] -where A is the collision frequency factor -e is the natural log base -R is the gas constant [math](8.314510 \times 10^{-3} kJ \ K^{-1} \ mol^{-1})[/math] -k is the rate constant for the reaction -Ea is the activation energy Is there a way to calculate the collision frequency factor, A, without just rearranging [assuming activation energy is unknown]? The collision frequency factor is supposed to be specific for every reaction, so there must be a seperate way to calculate it for it to be of any use.

hey guys, may you're interested in such thread... I'll start and who gives the right answer has to ask next question! allowed are all chemical compounds which have been confirmed. ............ here is a simple one: it consists of an element in the 6 main group and two other elements, you shouldn't drink that, also it is very often used in syntheses. One of the other elements is very light and the second other element is necessary in combustions ?

Welcome. Perkin reaction. The Perkin reaction is an organic reaction developed by William Henry Perkin that can be used to make cinnamic acids by the aldol condensation of aromatic aldehydes and acid anhydrides in the presence of an alkali salt of the acid. Reaction mechanism: The above mechanism is not universally accepted, as several versions exist, including decarboxylation without acetic group transfer. Source: http://en.wikipedia.org/wiki/Perkin_reaction Thanks.

i think i have a rock of pure silicon, what is something like this worth? it is about 1 inch high.

Hi I'm looking for a substance that that could clot together to glue two bits of rubber or leather together. Does this sort of substance exist? Any help appreciated! Many thanks Charlie

So, this may take a bit to explain: Since I was a kid, I have always loved survivalism, and have been fascinated with how I'd manage to live after some large-scale, more or less civilization-ending event. (You can imagine my teenage disappointment when Y2K passed without incident.) I am committed to reason, science, and progress, and I certainly don't honestly long for the end of civilization--it's less likely I'll live to 500 years and see the mountains of Mars that way. Nonetheless, I have always found planning for "The Crash" to be a great intellectual exercise and pleasantly all-consuming fantasy. My question here is this: suppose civil society was gone (…

I've made topics before about water electrolysis... never got around to actually doing said electrolysis though. But I've heard of alternative means of making hydrogen, such as mixing strong acids with metals. I'm guessing that would be more expensive and/or wasteful than electrolysis?

I always have difficulty accepting the analogy between the flowing of electrons because of potential differences and water flowing downhill. The reason is shouldn't electrons begins to flow once the wire is connected to it? Why does it needs a complete circuit? This is a very general question, and I hope someone could get my thinking in the right direction.

Sorry to bring this topic again, but I recently came into a batch of those small "bracelet-type" glowsticks. it was the unused remains of a party, about 100 of them. So I thought to myself "cool, i'll be able to retrieve the individual chemicals from these and put them to good use". The H2O2 is always very useful in high concentrations to precipitate the iodine in a solution, i'll have a bunch of different dyes I can use for my future plans for a nitrogen laser, and I know that TCPO is hard to make and expensive (I have basically no use for it, but heck, if I ever need it...) So I decided to start "disassembling" these little glowsticks, always being careful and…

This Saturday I am going on a one week campout. Due to fire hazards, we are not allowed to bring any fireworks to the campout on the 4th of July. But, since it will be the fourth, the scout leaders have said that we will have a contest to see who can build a fire in the most creative way. But the conditions are: 1. It cannot be explosive 2. It cannot create any hazardous materials such as chlorine or molten iron. 3. You have to be able to buy the ingredients from a local walk-in store. Is there any fun experiments that make fire that I could use? Btw, it would help if I could get some idea's before this Saturday. Thanks a million.

Adding alkali metals to anhydrous ammonia produces what basically amounts to a solution of alkali metal cation (I) and a solvated electron. These solutions are often and unofficially reffered to as "electride" solutions. My question is: what happens to the solvated electron upon photo-excitation? For example, what kind of UV-vis or EPR spectrum might arise from characterization of this solution. The physics of these solutions are poorly understood at best as far as I know, (correct me if I'm misinformed). On a side note, these solutions undergo interesting color shifts as concentration changes. The completely saturated solution takes on a golden metallic luster for …

I've read that Francium is so rare that no more than 30g Exists on earth at any one time. What makes Francium exist in much lesser quantities than some of the other alkali metals?

Using PCl5 as an example. In PCl3 each 3p orbital is involved in bonding. In PCl5 I'm guessing the 3s electrons which are usually P's lone pair of electrons are snatched by the electronegative Cl atoms. I read that P holds the extra electrons from the 2 extra bonds in its 3d orbital. Does that mean 1 bonding electron resides in the s orbital while the other one resides in the d orbital?

This provides audio/video courses and lectures in chemistry and chemical engineering from colleges/universities. http://www.infocobuild.com/education/audio-video-courses/chemistry/chemistry-and-chemical-engineering.html The courses and lectures include general chemistry, organic chemistry, inorganic chemistry, introduction to chemical engineering, and chemical structure and reactivity.

I'm trying to get my head around the whole doubling of CO2. Is there a procedure to calculate it? Also what physical feedback processes affect the value?

Hello everyone, I have a quick clarification. Enzymes are not consumed in the reaction but cofactor like NAD+ is consumed in reaction right. So does NAD+ first bind to the enzyme and then get reduced in certain reactions? Thanks

Hey All, Thanks for your help in the last thread. Here's a new one. Hope you have time and the curiosity to assist with this more detailed request. Basically, I have little to no scientific bent and need help. I am looking to freeze a rectangular block of crude oil (800mm x 800mm x 75mm in depth). So far, getting my hands on crude oil has been quite a task, requiring quite a lot more research than I had anticipated. It seems that prior to any of the oil refineries handing over any crude, I need quite a detailed manual on how I plan to use it. They have issues with regards to “duty of care”. The basic premise thus far, is to create a rectangular wooden…

Hello everyone, Why is that when denature protein you can't get it back to orginal shape. Practically it is obvious that when you burn something it is not going to come back for original shape but what is the chemical basis behind this. Are molecules loss or, heat loss or why is it this so. Why does extreme cooling can not get it back to orginal shape. Thanks

Hi I am trying to figure out the right liquid to use that has the following properties: optically clear/colorless refractive index of 1.490 viscosity of 5cSt or lower at 25oC compatible with PMMA and either polyurethane elastomers or silicone elastomers. I have looked at mineral/white oils but can not get to a sufficiently low viscosity and the index value. Thanks

If I put a piece of charcoal in a metal clamp (for pressure) and set the focal point of a fresnel lense on the charcoal (for heat) would this be enough to squeeze the carbon atoms in the charcoal together to form diamond lattice?

What do the reactions of Litmus paper with an acid look like? with a base? I'm guessing it's (organic structure of litmus) + acid ---> red (organic structure of litmus) + base ---> blue I'm looking for molecular structures that describe these processes. Any suitable molecule for an acid or base would be fine.

During the summer I've been studying chemistry by myself to prepare myself for college. I'm currently stuck on the topic of crystal structure. The book is trying to explain graphing the structures on a coordinate plane and finding interatomic distances between the atoms using Angstroms. It's pretty confusing can anyone help explain?

as everyone knows mars is red for its iron oxide but what i dont know why mars why not earth or pluto so it is all over mars but what are the chemical compounds for mars that do this:confused::confused::confused::confused: