Which among the following has the highest boiling point?

What is the product obtained when acetamide is treated with nitrous acid $(HNO_2)$?

Which of the following has the most acidic hydrogen?

What sized ring is formed when two carboxylic acids form a dimeric structure through intermolecular hydrogen bonding? (Consider the hydrogen bond as a bond in the ring structure.)

The major product of the following reaction sequence is:

In the following sequence,products $I$,$J$ and $L$ are formed. $K$ represents a reagent.
$1.$ The structure of the product $I$ is
$2.$ The structures of compounds $J$ and $K$ respectively are
$3.$ The structure of product $L$ is
Give the answer for questions $1, 2$ and $3.$