Chemistry: Post your doubts here!

[The Chill Master]

View attachment 51114

Is the answer A
I got it since Nickel in the presence of hydrogen can reduce C=O as well as C=C
over here we have got a total of 3 double bonds and one bond breaks to form to sigma bonds mean there should be 6 new atoms attached.
1 mole = H2
so just assuming hydrogen atoms add on C=O
since there is space for one moremole so it will get attached on C=C
now on the last double bond
1 mole of Br2 gets attached
since the answer i got is 2 & 1
so nearest to it is A

 

[Metanoia]

Is the answer A
I got it since Nickel in the presence of hydrogen can reduce C=O as well as C=C
over here we have got a total of 3 double bonds and one bond breaks to form to sigma bonds mean there should be 6 new atoms attached.
1 mole = H2
so just assuming hydrogen atoms add on C=O
since there is space for one moremole so it will get attached on C=C
now on the last double bond
1 mole of Br2 gets attached
since the answer i got is 2 & 1
so nearest to it is A

I think you misunderstood the question.

They are asking how many moles of H2 and Br2 for separate experiments.

H2 in nickel does not reduce COOH groups.

Also, if you do get a solution that is none of the 4 options, it's an indication of being wrong, do not simply choose the nearest correct answer,

 

[The Chill Master]

I think you misunderstood the question.

They are asking how many moles of H2 and Br2 for separate experiments.

H2 in nickel does not reduce COOH groups.

Also, if you do get a solution that is none of the 4 options, it's an indication of being wrong, do not simply choose the nearest correct answer,

Oops but Nickel in the presence of hydrogen can reduce C=O as well as C=C right?

 

[Metanoia]

Oops but Nickel in the presence of hydrogen can reduce C=O as well as C=C right?

Hydrogen will not be able to reduce the carboxylic acid group.

To reduce the acid group, we need LiAH4 (lithium aluminum hydride).

 

[My Name]

One H2 adds across each C=C bonds, same reasoning for Br2.

So 2 moles for both.


Which years are these from?

Okay...Answer is A
I don't know I'm solving these from the classified ones I found online ignore question 10 can you help in quetsion 9 and 11 ?
Please and thank you

Is the answer A
I got it since Nickel in the presence of hydrogen can reduce C=O as well as C=C
over here we have got a total of 3 double bonds and one bond breaks to form to sigma bonds mean there should be 6 new atoms attached.
1 mole = H2
so just assuming hydrogen atoms add on C=O
since there is space for one moremole so it will get attached on C=C
now on the last double bond
1 mole of Br2 gets attached
since the answer i got is 2 & 1
so nearest to it is A

Yes answer is A

My brain feels blocked!

 

[The Chill Master]

Hydrogen will not be able to reduce the carboxylic acid group.

To reduce the acid group, we need LiAH4 (lithium aluminum hydride).

But in aldehyde it will right?

 

[The Chill Master]

View attachment 51115
Answers
B
C
B

9 th one is easy you can straight away strike of A since an ester should have been formed and it's not frmed
B is fi9 cuz Oh is replaced with an acid group
C is fi9 too but according to how i see if i wouln't have any other choice then i would have gone with C the reason why i amn't chosing C is because O-Na+ can rduce H from Carboxylic group
D has the same problem as C Cl group can reduce the other OH part also so B would be the rather only sensible one

 

[My Name]

9 th one is easy you can straight away strike of A since an ester should have been formed and it's not frmed
B is fi9 cuz Oh is replaced with an acid group
C is fi9 too but according to how i see if i wouln't have any other choice then i would have gone with C the reason why i amn't chosing C is because O-Na+ can rduce H from Carboxylic group
D has the same problem as C Cl group can reduce the other OH part also so B would be the rather only sensible one

Okay Ty
same here I thought of A and C!

 

[The Chill Master]

Okay...Answer is A
I don't know I'm solving these from the classified ones I found online ignore question 10 can you help in quetsion 9 and 11 ?
Please and thank you

Yes answer is A

My brain feels blocked!

Online

 

[My Name]

Online

I meant from XPC

 

[The Chill Master]

View attachment 51115
Answers
B
C
B

11 th one i can't say anything
Saad.A.K in need of help

 

[The Chill Master]

I meant from XPC

lel

 

[The Chill Master]

View attachment 51115
Answers
B
C
B

Okay look A and C are cancelled since they don't contain R2 now we are left with B and D
And in D it looks like an cis- trans isomer so i will go with B

 

[My Name]

Okay look A and C are cancelled since they don't contain R2 now we are left with B and D
And in D it looks like an cis- trans isomer so i will go with B

Hmm..okay

 

[The Chill Master]

Hmm..okay

I ain't sure though just a guess or typically what i assumed

 

[Metanoia]

Okay...Answer is A
I don't know I'm solving these from the classified ones I found online ignore question 10 can you help in quetsion 9 and 11 ?
Please and thank you

Qn 9.
A. Wrong. Cause the ester group is formed on the wrong location.
B. Correct. Ester group formed between the alcohol and acid functional groups.
C. Wrong. This is supposed to be an acid + carbonate reaction. The COOH should be the one forming COO-Na+

Qn 11.

Check for trans isomerism (use "diagonally opposite H atoms as a guide), A and B are possible answers.

Between A and B, B is optically active as it has a chiral carbon (carbon joined to 4 different groups).

So B is the answer.

My suggestion is to try questions organized in years, so that it is easier to check within the forum if the question has been answered before. But ultimately, its your preference.

 

[My Name]

Qn 9.
A. Wrong. Cause the ester group is formed on the wrong location.
B. Correct. Ester group formed between the alcohol and acid functional groups.
C. Wrong. This is supposed to be an acid + carbonate reaction. The COOH should be the one forming COO-Na+

Qn 11.
View attachment 51116
Check for trans isomerism (use "diagonally opposite H atoms as a guide), A and B are possible answers.

Between A and B, B is optically active as it has a chiral carbon (carbon joined to 4 different groups).

So B is the answer.

My suggestion is to try questions organized in years, so that it is easier to check within the forum if the question has been answered before. But ultimately, its your preference.

Yes I was a bit confused with A and C.
Okay Ty
The topical papers I got from here had the ANSWERS for MCQ's so I checked from there.You are right,though.

 

[princess Anu]

can somebody explain this example
High charge density causes increase in covalent charater OR ionic character? :s

 

[princess Anu]

What is the reason for the change in the shape of the graph for BOILING and Melting Points? :/

 

[exploded diper]

can sumbody explain me q16
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s07_qp_1.pdf