Chemistry: Post your doubts here!

[Suchal Riaz]

another thing:

when we use KMnO4 on alkyl benzene.

say we had benezene-CH2CH3.
what would be the product?
benzene-COOH or benzene-CH2COOH

also:

halogenation of phenol has 2 cases,
one where Br(l) in a non-polar solvent is used. a mixture of 2-bromo phenol and 4-bromo phenol is produced
On wikipedia it says that the reaction is faster in polar solution so in water it would be faster so there is more chance of 2,4,6. but if you use non-polar solvent and heat it and have Br2 in high concentration you can still get 2,4,6.


and one Br(aq)
2,4,6, bromo phenol produced.

is this correct?

btw.. thank you soo much Suchal Riaz
I remember you from last year bro,
congrats soo much on your distinction(saw your name in the list in feb and was soo happy for you). MashAllah!

When an alkyl is attached to a benzene ring directly it would be converted into benzoic acid. no matter what that alkyl. it would always be

(2) as far as I know a concentrated or heated Br2(aq) would produce 2,4,6 but milder conditions would produce just 2 or 4

(3)Thank you. If you have any other doubts please let me know.

 

[hamzashariq]

I have a couple of questions which I was hoping somebody could help me out with.

1- Any notes on the Soil treatment(sorbents and stuff) and nano technology of applications, I got less time so something short will be appreciated.

2- I just want to confirm the conditions for ester hydrolysis. is it the same as that of hydrolysis of an amide linkage?

Ester hydrolysis requires reflux whereas amide hydrolysis does not.

 

[Bba321]

This was actually a blunder CIE made. They shouldn't have given this question because average students dont know that in COO there is a delocalisation between COO like this:
View attachment 53352
so the lone pair that is actually donated to the ring is used up in this delocalisation that means that the ring isn't 'activated' as you call it.

Okay thanks a lot

 

[Suchal Riaz]

Ester hydrolysis requires reflux whereas amide hydrolysis does not.

reflux actually depends on the reagents. if the products/reactants are volatile they need reflux. otherwise not. if there is a very complex and large molecule with ester links it would not need reflux just heat because it wouldn't evaporate. small esters such as ethyl ethanoate must need reflus as both products and reactants are very volatile. they evaporate even without heating.

 

[anonymous1122]

What were the ions in the salt? Chem p33?
And answer to last part? Was it oxodized or not?

 

[danial 234]

How to solve this?

 

[Nowrin Yasmin]

Can anyone please give a clear explanation of whether the ease of hydrolysis of group IV tetrachlorides increase or decrease down the group? including the reasoning.

 

[forsaken]

hey is OH an electron withdrawing group?

 

[danial 234]

hey is OH an electron withdrawing group?

OH is an electron donating group

 

[Suchal Riaz]

View attachment 53371

How to solve this?

 

[hamzashariq]

Can anyone please give a clear explanation of whether the ease of hydrolysis of group IV tetrachlorides increase or decrease down the group? including the reasoning.

Ease of hydrolysis increases as the metallic nature of the elements increases.

 

[danial 234]

View attachment 53381

View attachment 53380

Thank you so much ^_^

 

[Metanoia]

View attachment 53371

How to solve this?

You can try viewing it from the end on the left side. Then visualize them as clock faces, using references with H and CH3 at the 12 o'clock positions.

 

[danial 234]

When A reacts with Br(qa) which group should we consider as the first one to put Br ? oh or c(ch3)3? And why?
Please help!! Thankyou

C(CH3)3 and OH both are electron donating groups.
Substitution will occur about ortho and para positions

 

[Bba321]

C(CH3)3 and OH both are electron donating groups.
Substitution will occur about ortho and para positions

Yes but with respect to which group?

 

[Kamihus]

Anyone has Examiner Report for Oct/Nov 2014?

 

[Metanoia]

Yes but with respect to which group?

Do you have a diagram of the compound? Or is it something you thought of?

 

[Bba321]

Do you have a diagram of the compound? Or is it something you thought of?

diagram got deleted :/ Br(aq) with A
June 2013/41 was 5 c

 

[Metanoia]

diagram got deleted :/ Br(aq) with A
June 2013/41 was 5 c

It would be in the 2 and 6 position with respect to OH.

OH is a stronger activating group compared to alkyl groups, there is also the issue of the steric hindrance of the large alkyl group.

 

[natashaatiq]

May I please get notes on nmr?