Chemistry: Post your doubts here!

[chocolate_girl]

I have some problem in organic chemistry can someone please elaborate these syllabus content for me

1)describe the formation of carboxylic acids from nitriles

2)describe the reactions of carboxylic acids in the formation of acyl chloride

3)describe the formation of amides from the reaction between RNH2 and R'COCl

4)describe amide hydrolysis on treatment with aqueous alkali or acid

Thanks in advance

 

[daredevil]

Suggest an explanation for the lack of reactivity of the nitrogen molecule, N2. [1]

 

[Namehere]

Suggest an explanation for the lack of reactivity of the nitrogen molecule, N2. [1]

Nitrogen triple bond is very strong.

 

[snowbrood]

ok guys here is my train of thought hope you follow(p.s I may be wrong so correct me if I am)
the compound has a total of 7 hydrogens and 7 carbons.
Now the peak at7.something confirms that it has a benzene ring. Now there must also be an OH that reacts with the Na metal but if we forma phenol with a chlorine attached it would leave a carbn short in our structure. so there must be an alcohol which is left which reacts with sodium metal as carboxylic acid would once again not fullfill the structure. now by attaching a chlorine and a methyl alcohol we remove 2 hydrogen and add three satisfying the no of Cs,Cls,Hs

bro this is not what i asked i know how to solve this type of question but what confuses me is why did the examiner say that the chemical shift value of secondary alkane is close to 4 when it should be 1.3 why is this the case was examiner drunk . in one paper he wrote (200/1.1) when he should have written 100/1.1 for finding the number of c atoms

 

[chocolate_girl]

Is this thread for as level students aswell?

 

[chocolate_girl]

What is the bond angle and structure of trigonal bipyramid e.g PF5

 

[Namehere]

What is the bond angle and structure of trigonal bipyramid e.g PF5

It is for AS students too.

It has bond angles of 90 and 120 degrees.

 

[chocolate_girl]

describe covalent bonding in terms of orbital overlap, giving σ and π bonds, including the concept of hybridisation to form sp, sp2 and sp3 orbitals
What is the concept of hybridisation?

 

[chocolate_girl]

It is for AS students too.

It has bond angles of 90 and 120 degrees.

Thankyou so soooo muchh would u please see my post above nd try to ans my queries? I will b greatful

 

[chocolate_girl]

It is for AS students too.

It has bond angles of 90 and 120 degrees.

Can u also make the image of the structure in my mind nd that does it have both 90 or 120 angle or only 1?

 

[chocolate_girl]

1. understand, in simple terms, the concept of electronegativity
   and apply it to explain the properties of molecules such as bond polarity (3h), the dipole moments of molecules (3j), the behaviour of oxides with water (3.1j) and the acidities of chlorine-substituted ethanoic acids (10.6c)
   
   Please explain me the last chlorine substituted ethanoic acid part aswell

 

[Namehere]

The answer to your questions can be easily found in your book and by researching on the internet. I would love to help everyone, but unfortunately I do not have the time to please everyone.

 

[chocolate_girl]

The answer to your questions can be easily found in your book and by researching on the internet. I would love to help everyone, but unfortunately I do not have the time to please everyone.

Its okay mayb somebody else will

 

[daredevil]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

Q4. if we do not branch C as given in the marking scheme ... see the snapshot. the elements are full and the alkene and carboxylic acid groups are there...
what am i missing?? or does it not make a difference if it is branched or not?

 

[daredevil]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_42.pdf
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_ms_42.pdf

In Q5, is it wrong to write just reduction instead of redox in the type of reaction G will hav with Na metal? Also how it is redox? the way i see it G is getting reduced and that is it.... ?? is it bcz it is losing H and also becoming negative (ox. state) that it is called redox?

 

[chocolate_girl]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_42.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_ms_42.pdf

In Q5, is it wrong to write just reduction instead of redox in the type of reaction G will hav with Na metal? Also how it is redox? the way i see it G is getting reduced and that is it.... ?? is it bcz it is losing H and also becoming negative (ox. state) that it is called redox?[/q
Sodium metal is oxidising from 0 to +1

 

[Amber]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_42.pdf

It has to be branched otherwise when the double bond is broken by hot conc H+ KMnO4 you willnot get compound E...Try working this question out from down to up

 

[daredevil]

It has to be branched otherwise when the double bond is broken by hot conc H+ KMnO4 you willnot get compound E...Try working this question out from down to up

then we can have a straight carboxylic acid too instead of the branched one (E) .......??

 

[Amber]

then we can have a straight carboxylic acid too instead of the branched one (E) .......??

you can but look at compound that undergoes reaction 3...it has a (CH3)2 so that bit has to remain coz reaction 3 is oxidation

 

[daredevil]

oooh right okay thannxx