Chemistry and Physics AS paper 12 MCQS

[MariamHASAN]

Hello,
I need help in the MCQS specifically in chemistry. I need to do the past papers but there are many questions i am unable to do and there are no answers written in the mark schemes. Please can some one help. Although i have the thousand mqs for chemistry but they are not so helpful as they are the singapore version!!!!

 

[MariamHASAN]

Can we start doing the papers yearly and discuss the problems together that will be a great help??????

 

[Sheikh Nahiyan]

Hello,
I need help in the MCQS specifically in chemistry. I need to do the past papers but there are many questions i am unable to do and there are no answers written in the mark schemes. Please can some one help. Although i have the thousand mqs for chemistry but they are not so helpful as they are the singapore version!!!!

Hey Mariam!

I can help you thoroughly in Chemistry but I myself need a lot of help in Physics :|
Inbox me if you need help in Chem

 

[MariamHASAN]

if we begin doin papers from 2007 and post the problems and discuss

 

[Sheikh Nahiyan]

if we begin doin papers from 2007 and post the problems and discuss

Sure Mariam! But logging here everyday, especially from phone is really tiresome. Do you have an email id? Can you inbox me your email id? Discussion over there will be easier!

 

[MariamHASAN]

isnt it possible to do here more people will also help

 

[Sheikh Nahiyan]

It is! but I do not sit at the computer much... :\ Just few hours in the day.. That's why I said it! No problem though.. I will help you anyways. I mean. I will try my best!

 

[MariamHASAN]

have u done all papers?

 

[MariamHASAN]

thanks

 

[Sheikh Nahiyan]

Finished doing all May-June papers from 2005 to 2010! Oct-nov papers a bit left. Got loads of time! Will do it later on

 

[MariamHASAN]

ok so ill send the problems soon

 

[Sheikh Nahiyan]

Ok!

 

[MariamHASAN]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s08_qp_1.pdf
How to do question number 6?

 

[MariamHASAN]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s07_qp_1.pdf
question 1 and 34?

 

[Sheikh Nahiyan]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_1.pdf
How to do question number 6?

Mass of 1cm3 of H2O = 1g
no. of moles of H20 =( 1/18 ) = 1.33mol

Now, solve this using unitary method:
Volume of steam at 298K = 1.33
Volume of steam at 1K = (1.33) / 298
Therefore, Volume of steam at 596K = (1.33 x 596 )/ 298 = 2.6666... round off to 2.67. So answer is C

 

[syed1995]

Count me in!

 

[Sheikh Nahiyan]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s07_qp_1.pdf
question 1 and 34?

Question - 1
To find the Relative atomic mass, always do it like this: (mass no. x relative abundance)/(relative abundance)
When there are 1 or more relative abundance, just do it like this:
[(mass no.1 x relative abundance1) + (mass no.2 x relative abundance2)] / (addition of the relative abundances)

Relative Atomic Mass = [(10x1) + (11x4) + (12x0)] / (1+4+0) = 10.8


Question - 4
1 is correct because it produces 2mol of gas(stoichiometric ratio is 1:2). And in the question it is said that R has a volume twice of S. (Suppose, 24cm3 gives 2mol, then 48cm3 will give 4mol)
So this makes the gas exert a pressure on the manometer and so the level of mercury will rise.
2 - stoichiometric ratio is 1:1, so doubling the volume will give same number of moles of gas. So there wont be any pressure to be exerted on the manometer and so the level of mercury will not rise. So 2 is wrong

As 2 is wrong, there are no other combinations, but to choose D

 

[MariamHASAN]

T

Question - 1
To find the Relative atomic mass, always do it like this: (mass no. x relative abundance)/(relative abundance)
When there are 1 or more relative abundance, just do it like this:
[(mass no.1 x relative abundance1) + (mass no.2 x relative abundance2)] / (addition of the relative abundances)

Relative Atomic Mass = [(10x1) + (11x4) + (12x0)] / (1+4+0) = 10.8


Question - 4
1 is correct because it produces 2mol of gas(stoichiometric ratio is 1:2). And in the question it is said that R has a volume twice of S. (Suppose, 24cm3 gives 2mol, then 48cm3 will give 4mol)
So this makes the gas exert a pressure on the manometer and so the level of mercury will rise.
2 - stoichiometric ratio is 1:1, so doubling the volume will give same number of moles of gas. So there wont be any pressure to be exerted on the manometer and so the level of mercury will not rise. So 2 is wrong

As 2 is wrong, there are no other combinations, but to choose D

Thanks it was really hhelpful!!!

 

[Sheikh Nahiyan]

T

Thanks it was really hhelpful!!!

You are welcome Knock me when you need more help

 

[goodluckayesha]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w06_qp_1.pdf
how to do the 1st question??