Chemistry: Post your doubts here!

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for p4 chemistry what are the topics assesed?? is it all thhe topics in the syllabus or only those parts in bold or only the topics found in the pdf you sent me??
 
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all the topics in the syllabus bt that are sum notes to be learnt easily in pdf file :)
 
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Dear chemistry i hate you so much!!! each molecule of my body is shouting "Hate you chemistry"!!!
 
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Emily793 said:
Dear chemistry i hate you so much!!! each molecule of my body is shouting "Hate you chemistry"!!!
Are you giving your A-level exams tomorrow (Chemistry paper 4) ?
 
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Doubt !!

(b) explain qualitatively in terms of intermolecular forces and molecular
size:
(i) the conditions necessary for a gas to approach ideal behaviour
(ii) the limitations of ideality at very high pressures and very low
temperatures
 
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(i) intermolecular forces shud be very weak or negligible as in most of noble gases and molecular size shud be as small as possible lioke hydrogen .....y???? cos KMT postualtes THAT molecular size is insignificant compared to volume taken by the gas.........
ii)at high pressure molecules are forced very close together so intermolecular forces start to operate, also molecular volume now become significant compared to vol of whole gas......so this contradicts the postulates of KMT....SO gas is no more ideal or it deviates from the ideal behaviiour
 
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Hi every1 !!! :) i just had doudt about the esters!!!!! for example if the coumpound is given {Ethyl Methonate} how wud write this compund !!!!!!!! :unknown: plz help !!!!! Thanks in Advance
 
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hey guys i just needed to clear out something since the exam is less than 2 days away.

ok so you know how in paper 2 there was structural formula related questions. where the questions ask you to write down the structural formula. ok thing is, i usually know my concepts but like my arrangement of the atoms in the structural formula turns out to be different that what is in the marking scheme. mind you, im not saying i write the wrong answer its just that, instead of (for eg): propan-1,3-di-oic acid, ill write: CO2HCH2CO2H. but in the marking scheme itll say HO2CCH2CO2H. now is my answer wrong or does it not matter at all? cos im just worried that i might lose marks this way. can someone please clear this out for me.
 
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It does matter in most cases. But in some it doesn't. For example in the cases of Alcohol and Aldehydes CHO and COH is a different thing.. In this case too, you should try to write the formula in the latter way. Though, yours is fine too.
 
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