Jump to content


  • Posts

  • Joined

  • Last visited

Everything posted by maskman`

  1. well, naoh i believe reacts to form alcohol and ch3ch2oNa with reacted with an ester. the alcohol comes from the ethyl part of the ester
  2. i attempted this question believing that is was naoh and na(s) had the same properties and would react simliarly to the ester. i was found to be wrong. why?
  3. wow never thought of it that way
  4. 18 The following two experiments are carried out with anhydrous potassium chloride and observations X and Y are made at the end of each experiment. Concentrated sulfuric acid is added to the potassium chloride and the fumes produced are bubbled into aqueous potassium iodide solution - observation X. The potassium chloride is dissolved in aqueous ammonia and this is then added to aqueous silver nitrate - observation Y. What are the observations X and Y? X Y A brown solution colourless solution B brown solution white precipitate C colourless solution colourless solution D colourless solution white precipitate please correct me if i am wrong by anydrous it means that it doesnt contain any water \ kCL+ h2so4 = k2so4 +2hcl and i dont know what happens when kcl reacts with silver nitrate and ammonia i dont understand the color thing yet. does it have a logic in it or is it just something that needs to be learned by heart? 21 An organic compound J reacts with sodium to produce an organic ion with a charge of –3. J reacts with NaOH(aq) to produce an organic ion with a charge of –1. What could be the structural formula of J? A HO2CCH(OH)CH2CO2H B HO2CCH(OH)CH2CHO C HOCH2CH(OH)CH2CO2H D HOCH2COCH2CHO is there even such i thing like organic ion? like i know that organic compounds can get - charge coo~ could be one group with such a charge. all in all i would guess that alchols and carboxylics acids can react with sodium and therefore the one with 3 groups carboxylic sodium and alcohol are responsible for this ions to be formed. please correct me if i am wrong
  5. 32 In a genetic engineering experiment a piece of double-stranded DNA containing 6000 nucleotides coding for a specific polypeptide is transcribed and translated. What is the total number of amino acids in this polypeptide? A 500 B 1000 C 2000 D 3000 33 Bacteria were grown in a medium containing 15N. After several generations, all of the DNA contained 15N. Some of these bacteria were transferred to a medium containing the common isotope of nitrogen, 14N. The bacteria were allowed to divide once. The DNA of some of these bacteria was extracted and analysed. This DNA was all hybrid DNA containing equal amounts of 14N and 15N. The remaining bacteria were left in the medium with 14N and allowed to divide one more time. The DNA of some of these bacteria was extracted and analysed. What is the composition of this DNA? A 25 % hybrid DNA B 50 % hybrid DNA C 75 % hybrid DNA D 100 % hybrid DNA what are your answers and why?
  6. I would say that they are very versatile, but in what regards are you studying them? I am trying to understand the way they react and interact with other compounds and their uses in both physical and chemical as Actually, I think the definition of alcohols (ie, having a =OH group) is too broad to have much meaning. Cholesterol is an alcohol, which our bodies need. Ethanol is an alcohol that our bodies can tolerate somewhat. Methanol is rather poisonous to us. There are cyclic alcohols, acyclic alcohols, simple alcohols, branched alcohols, etc depending on shape of their carbon "backbones". i really want to know the basics first and move on to more complex ones. i didnt know cholestrol was a alcohol! wow. really keeps some insights in biology where cholestrol is a very discussed topic. i heard about ethanol and methanol from my college though. why do shapes play sooo much influence on the chemical properites of an alcohol?
  7. quote Our immune system has evolved in a way that somewhat makes up for the vast differences in generation time between bacteria/virus and humans (minutes/hours vs years). i couldnt agree more. even before medicine was developed a average human could live up to 40 years. compared with the few hours of life span of bacteria. quote During this response a high affinity antibody (high affinity to the ivading pathogen's antigens) will be developed, and it is at this point when this specific antibody will become much more prelavent (temporarily). so only when there is invasion will the lymphocytes be produced and will decrease in number when the number of pathogens have decrease or stopped invading. however i do have one question Affinity maturation of antibodies by somatic hypermutation introduces variation. Then clonal selection of the highest affinity antibodies are selected, and then mass produced. does this mean the those antibodies which have the highest affinity survive and get passed on to the next generation?
  8. swansont The total energy of anything at rest is not zero — it is mc^2. The is not a momentum equation, it is an energy equation. If the object is moving, the relevant equation is The momentum of a photon, which is massless, is E/c. Conservation of momentum and energy involving a photon and a massive object is a path for deriving E=mc^2 and lets you see where the c^2 comes from. respected swansont, You yourself have quoted that energy is not momentum. a moving body has kinetic energy. but i agree on the fact that energy is dependent on mass and velocity. i think this is what your trying to say to me. that being said i know that the moving body doesnt not get its energy from the equation e=mc^2. momentum it gets it from the equation, kinetic energy= 1/2mv^2 now if you suppose a body is moving at the 90% the speed of light. it has a velocity of 3 * 10^7. say this body has a mass of 5 kg. now its K E is 5/2*(3*10^7)^2. agreed? ke =2.25*10^15 now this energy according to einsteins theory e=mc^2 adds up to the mass. e=mc^2 e= KE m= KE/c^2 about 0.025 which adds up to the mass of the object and is about 0.5 % of an increase in mass. which is not much but the more a person moves towards the speed of light the more the energy adds up to the mass. cheers please correct me if i am wrong. thx for replying
  9. momentum is force * time. ma*t = mv*t/t =mv which is different from mv2 which has a square on v. momentum does not have a square on it. which is the equation of momentum. this is a equation about energy =force * distance =f*d =ma*d =mv/t*d =mv2 so mass and energy are equivalent and interconvertible. e=mc2 in this e is energy and m is mass and c is the speed of light. here we know that the speed of light is tremendous and that value is very large. that is trying to say that a small amount of mass can be converted to a large amount of energy. and a large amount of energy can be converted to a small amount of mass. now it also has implications in velocity. when a object is moving with certain velocity it has certain amount of kinetic energy. this energy kinetic adds to the mass of the object and makes it heavier. however this value is small at smaller velocities but only significant for the bodies near the speed of light. the more the body moves towards the speed of light the more the energy adds up to his mass and has a rather significant impact on it. this theory i believe has also implications in proving that a accelerating body is space feels similar laws to a body that is within a gravitational field of a big mass.
  10. why are alcohols so important. we need to study a whole chapter about it. i know the following facts 1) it is used to make ethanol a clean fuel that in theory would not increase the amount of carbon emissions in the atmosphere. 2)it is used to make ethene under the presence of Al203 catalyst which lowers the activation energy for this dehydration to take place. 3) it is used to make ester with the help of carboxylic acid. 4) it is used to make carbonyl compounds by its oxidation by k2cr2o7. it turns yellow green. 5) it is used halogenoalkenes by nucleophilic substitution reaction. 6) it can even react with sodium for where sodium attacks the electron dense oxygen atom in the 0h group and replaces Hydrogen. why are alcohols so important ? are these points enough to describe the wonder of what alcohol is ?
  11. CharonY so basically a wide range of different antibodies by genes is produced, but only those antibodies which combine with the bacteria are produced more in more. so more antibodies that fit with the bacteria are found more in number in our body. natural selection it is indeed ! thx for the link iNow
  12. iNow yes the cardiovascular system and the nerve system are indeed wonders and the advances of chemistry and biiology has gifted us with a deeper perspective of understanding the grand design behind it. yes i do , i want to know all about the basic functioning of the immune system.
  13. nice to hear about your visit to glastonbury and being recommended such a wonderful second hand book. sry about your lack and of time and too much work to do though. yes i think bohm so far gives some insight and is indeed a good read. i am staying china right now and i got it from a chinese library. i wanted to read something by the greatest physicist according to wikipedia of the last century. haha it indeed gives a perspective contrary to what most physicist think today especially with the hidden variable. i heard he predicted the higgs bosom . and now the discovery of it 20 years after his death indeed serves as a legacy for his contribution.
  14. i was wondering the wonder of the immune system and how all the things are kept in place so that we survive the infectious diseases, or that our children survive the infectious disease. we would have been dead had it not been for those antibiotic protein molecules which stop the bacteria from invading by various means. stoping them or destroying their walls. artificials antibiotics have helped mankind tremendously. how does this take place so unconciously. this question has fueled my curiousity.?
  15. carbon is the essential component of organic chemistry. it can easily combine with hydrogen and oxygen. the ones that are bonded with hydrogen are called hydrocarbons. now that being said there are many things that our body needs. firstly it need glucose, for energy is released when it is broken. this is a hydrocarbon chain (glucose). it is a aldehyde to be more specific meaning the end of the carbon chain is bonded to a oxygen. secondly it needs lipids for storage of energy and protection as it forms a layer. this again is formed by carboxylic acid which is a hydrocarbon chain which the end Carbon contains a double bond O and bond OH. finally it needs proteins which are the building blocks of our body. they are made of carboxlyic groups and amines bonded to a hydrocarbon chain. amines meaning NH2. i would say this is one of the most important things we have in our bodies they do a range of functions ranging from hormones, to enzymes, to mucus which play a great role in protecting our body. to sum it up i would say we would all be dead if we didnt have carbons in our body. source a level chemistry a level biology discovery channel
  16. to arkn well it all boils down to a very interesting fact that the speed of light is constant no matter what and that the gravitational force doesnt slow the speed of light but in fact it bends it. they found this out both mathematically and experimentally. imagine two cars moving towards each other. now they would reach each other faster because the relative velocities add up. however imagine a person light sec away from light that is about 3 hundred million metres. since the speed of light is constant light will reach him in one sec. however if the person moves towards the light the relative velocity does not add up because of the speed of light is constant. however the distance to be covered by the light has decreased. S=C/t the relative velocity is constant. and the distance has decreased. to maintain a balance it would take more time for light to reach the user. now it would only make sense that the time has has slowed down for the user. for your question on how things slow down in black holes we need to understand two things. 1) that acceleration in the space is simliar to that of the gravitational field within a planet. that means that when your in a rocket accelerating in space or a rocket in the earth gravitational field at rest. you would not know the difference. 2) understand how a person standing at a top of a accelerating rocket feels different time to a person stand at the bottom. at rest lets say that a person on the rocket at the top is at a certain distance from a person at the bottom. say 1 light sec is this distance. the people have 2 stop watches. a person 1 gives a signal of light to the bottom. person 2 recieves it after one sec. the time interval is one sec. person 1 sends the second signal at time=2. person 2 recieves signal at time=3. conclusion the person receives the signal at equal intervals at which it is send. at constant velocity person 1 sends signal. person 2 receives signal earlier than 1 second say at t= 1.98 because of constant velocity. person 1 sends signal at time =2. person 2 receives the signal earlier than 1 second by the same amount say at 2.98. time interval in which it is send ie sec is equal to the time interval the other person receives it . however in a accelerating rocket . person 1 sends the signal. person 2 reclieves the signal ealier than 1 sec say t=1.98. person 1 sends the signal at t=2. person 2 receives the signal earlier than 1 sec earlier but even quicker at the velocity is more for an accelerating rocket. say 2.97. the time interval in which the signal is the send is larger than the time interval in which the signal is recieved. that is trying to say that you age more quickly at the top of the rocket than at the bottom. well this is pretty significant in itself but it is even more significant to know, that this works in terms of the earths gravitational field as well, according to the two points discussed above. a person at the top of the mountain ages more faster than the person near the sea level. this is also proven by experiment. this is because the earths gravitational field plays the same effect as a accelerating rocket. regards hope this helps. source : stephen hawking brief history of time a level physics student
  17. i was reading david bohm and he seems to be extraordinarly clear in what he talks about. he talks about how everchanging our thoughts are related to context and how our thought leads to fragmentation. any thoughts on bohm. please feel free to discuss.
  18. my understanding of emphysema seems to be flawed. i thought it was because of the lung inflamation that microphages attack and invade the alveoli 100%.. but i am not 100% this is sure. can anyone give me some more details about this please.
  19. hahah thx a lot lota it helped a lot. i understand much more now thank you
  20. umm i was wonder about this question . in my chemistry book it has shown br losing all its electrons and combining ethene. i was wondering whether this bond is co ordinate for not because it seems that ethene is donating electrons to the electron deficient bromine. any help is much appreciated
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.