2ei)
This question maylook intimidating at the first glance. The way to approach this question is to look for clues in the question itself. First you would notice that the ratio of carbon atoms to hydrogen atoms is close to 1:1. Most of the time, this 1:1 ratio suggests that a benzene ring is present. This is supported by the structure shown in C which indeed contains a benzene ring.
A is able to react with thionyl chloride SOCl2. This suggest that an alcohol function group or a carboxylic acid functional group is present. Alcohols react with thionyl chloride to form alkyl chlorides and carboxylic acids react with thionyl chloride to form acyl chlorides
However the alkyl chloride product does not have any oxygen atoms. This suggest that the functional group present is carboxylic acid .
2eii)
Reaction I is an acid base reaction
OH- abstracts a proton from the amide linkage forming water, N- and Na+.
Reaction II is a Nucleophilic substitution reaction.
The N- generated acts as a nucleophile and substitutes bromine.
Recall that the C-Br bond is polar, with carbon carrying a slight positive charge. The slightly positive carbon attracts the N-.
Reaction III is a hydrolysis reaction.
The amide linkage is hydrolyzed to carboxylic acid and amine functional groups
2eiii)
Reagent: HCl
Condition:Heat
Side note: You would notice that for essay questions, the examiners like to mix 2 different topics in one question. In this case the first portion of the question is about inorganic chemistry (which i have not solved) and the second portion is about organic chemistry. This style of questioning is especially detrimental to students who like to "spot" topics. My advice is dont spot topics. Moreover for organic chemistry the topics only make sense if you study all of them together as they are all interlinked.
For those who are interested, the diagram below illustrates how the cyclic amide linkage is formed.
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