Chemistry Paper 2

[no.mercy]

so guys maths paper the most damned paper has ended..lol..i hope we all get at least an A in it..CIE i love you for making a good maths paper ;D

Anywayz, tommorow is our chemistry paper so post any guesses,notes,Q and A you have...good luck

And here i start with the following notes:

1) http://www.docbrown.info----------it is the best website for getting O levels Chemistry Notes and also it provides very helpful worksheets which can be solved online and checked automatically.

2) Chemistry notes posted by salmanpak...they are of 22.08 Mb of size..so better hook up on DSL if you are on dial-up and dont forget to thank him for his notes if they benefit you.http://www.mediafire.com/?veeocs84s2jchfj


3) http://www.gcse.com is also a quite cool website for O levels Study purposes so you can take help from it too esp regarding the new topics in the chem syllabus which are not covered in our books.
:beer:

 

[CaptainDanger]

What is the NEW topic? Not mentioned in the BOOK?

 

[no.mercy]

sorry i meant topics..sigh lack of proof reading

topics are such as the macro molecule topic..it hasnt been fully covered in the books (i am talking about federal and discover chemistry)

 

[CaptainDanger]

What is missing in the Federal book from the last topic??? I can't see much of a difference in the past papers questions related to that topic...

 

[no.mercy]

have you seen Keypoints Chemistry by Redspot? if you compare it with the federal..federal doesnt fully covers the criteria regarding macromolecules and whats the point of arguing.. arent we going off-topic?

 

[CaptainDanger]

I am not arguing... Don't take it that way... I got the paper tomorrow as well, don't want to miss anything! As long as its related to STUDY its not going off topic... If you see Biology Key Points there is difference in it as well... There are a little things in it not not really from the syllabus...

 

[no.mercy]

ok dude whatever the case is good luck for your paper

my advice: do metals and non-metals pastpapers and organic chem past papers from topical..rest is not needed much but do read whole of the book/keypoints

 

[CaptainDanger]

Ok... To you too...

 

[amazon]

N03 p2 Q A3 b.
Please solve.

 

[amazon]

another qs please..
when the mixture of styrene and butadiene polymerises, the polymer is unlikely to contain only this regular, repeating pattern. Explain why N03 B11 c

 

[abcde]

another qs please..
when the mixture of styrene and butadiene polymerises, the polymer is unlikely to contain only this regular, repeating pattern. Explain why N03 B11 c

Polymerisation is a random process. Styrene may form a bond with another styrene molecule instead of butadiene. Similarly, two butadiene molecules may join together. So it is unlikely that only this regular, repeating pattern will be produced.

 

[amazon]

and here a third one from the same paper
2.90 kg of butane entered the cracking tower. After the reaction, 2.16 kg of butadiene had been made
calculate the percentage yield of butadiene

 

[amazon]

C4H8 -----C4H6+ H2
plz give an explanation :unknown:

 

[abcde]

Mr. of Butane= 4(12) + 10 = 58
No.of moles of butane used = 2900/58 = 50 mol.
=> No. of moles of butadiene formed = 50 mol.
Mr. of butadiene = 4(12) + 6 = 54
=> Mass of butadiene (theoretical yield) = 50 x 54 = 2700.
Percentage yield of butadiene = 2160/2700 x 100% = 80.0%.

 

[amazon]

So what we take out is theoretical and what is given in the qs is experimental. Is this always the case. Should I remember it this way?

 

[abcde]

Yes, you can. The theoretical yield is the one which we calculate using the mass of the reactant. By definition, it is the calculated amount of product that would be obtained if the reaction is completed. The experimental yield is mentioned in the question.

 

[scouserlfc]

GUd luck for the paper guys !!

 

[ibadsiddiqi]

I LOVE chemistry..

 

[scouserlfc]

really then u r one of the few like me !!! i love it too but many hate it :x

 

[Soulgamer]

Chemistry is easy but cant study today! probably because tomorrows the last exam and today the maths paper went awesome.