Chemistry: Post your doubts here!

[amina1300]

Q 11 30 23 28 http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w16_qp_13.pdf
ans =C B A A

http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w16_qp_12.pdf
Q30 Q26
ans= B and C
Metanoia Please help

 

[Metanoia]

Q 11 20 29 http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w16_qp_13.pdf
http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w16_qp_12.pdf Q30 Q26
Metanoia Please help

I can't seem to access the papers. Are you able to post images of the questions directly here?

EDIT: Ok wait, I think I've got it, give me a while to look through them. For me to work faster, do you have their respective answers?

 

[amina1300]

I can't seem to access the papers. Are you able to post images of the questions directly here?

EDIT: Ok wait, I think I've got it, give me a while to look through them. For me to work faster, do you have their respective answers?

Fixed and edited it.

 

[amina1300]

http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_m16_qp_12.pdf
Q21 How can it be isomerism all 4 are the same
Q37

 

[Metanoia]

Q 11 30 23 http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_w16_qp_13.pdf
ans =C B A

I'm not sure why I am unable to attach diagrams at this moment..
Q11
Answer: C
A reaction with autocatalysts will start off relatively slow.The rate of reaction will increase due to the production of catalysts. After a peak, the rate of reaction will decrease when the concentration of reactants are used up.

Q23
Answer: A
Sulfuric acid will hydrolyse the ester bond and create a COOH group.
The C=C double bonds in the molecules will be hydrogenated.
The COOH bond will NOT be reduced to an alcohol by the hydrogen, that would actually require LiAlH4.

Q30
Answer: B
Esterification of the both OH groups with two COOH groups (1 from each molecule of ethanoic acid)

 

[Metanoia]

Q30 Q26
ans= B and C
Metanoia Please help

Q26 is the same as variant 13, which was explained.

Q30
Chiral carbon is marked in red

 

[SohaibButt]

Bond dissociation energy is a measurement of the strength of the covalent bond holding the atoms together within the molecules, and not the measurement of the strength of the bond among molecules.

can u clarify it more I'm still confused :/

 

[Metanoia]

http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_m16_qp_12.pdf
Q21 How can it be isomerism all 4 are the same
Q37

S16qp12
Q21
Focus on the groups at the C=C bond, notice that the groups diagonally opposite each other are different for the two molecules (geometric isomers)



Q37
Sodium will also react with the hydroxyl OH group, so option 1 is out

 

[Metanoia]

can u clarify it more I'm still confused :/

 

[SohaibButt]

View attachment 62413

Thank you

 

[Mstudent]

View attachment 62404

could you plz explain why you left out the fifth carbon?

 

[Mstudent]

Hey I need help in the Mcq paper 11 for chemistry which I'm gonna write on Wednesday 7th June if anyone writes it before 5am gmt pls share the question paper or the questions which come in it its a deep request someone pls help..it would be a huge favor for me.. Thanks.. Reply asap of anyone sees this msg

listen
1. If you look at the top of this page, there is a notice telling you not to disscuss about the paper 24 HOUR after the exam, IF you do you will be BANNED
2.You have to consider everyone's effort here man, everyone of us is working hard, Just work hard, and good luck, cheating is a sin BTW!

 

[amina1300]

could you plz explain why you left out the fifth carbon?

.
..Look at this Its actually the same thing, i t doesnt matter where you place the CL

 

[amina1300]

Q26 is the same as variant 13, which was explained.

Q30
Chiral carbon is marked in red
View attachment 62411

Q30

 

[darks]

Q30 View attachment 62417

Ans is B. And no it is not the same thing. Cis trans isomerism is due to "restricted rotation" of Pi bond over Sigma bond, that is the reason they are cis trans "isomers". The only difference in B and D is that B is trans and D is cis. We need to identify the "trans" so that is B. (Both B and D are optically active due to presence of chiral carbon. But only B is trans)

 

[darks]

Help in both please! Also if you guys need March 2017 p1, i have it.

 

[Mstudent]

View attachment 62421 View attachment 62422
Help in both please! Also if you guys need March 2017 p1, i have it.

Could you plz send it to me??? Your help will be greatly appreciated!

36. is A ONLY NaBr and NaI are oxidised when reacted with dil H2SO4, NaCL is too strong to be oxidised
37 is B I suppose? Find 'n' from PV=NRT to find the gas with the least moles!

hope that helps

 

[Mstudent]

View attachment 62416.
..Look at this Its actually the same thing, i t doesnt matter where you place the CL

Thank you very much Amina! Jazak Allah Khair!

 

[dumbledore.]

C

 

[dumbledore.]

A.
Why is 3 correct?