The increasing order of acidic strength among the following compounds is
$I.$ Benzoic acid
$II.$ $4-$nitrobenzoic acid
$III.$ $3, 4-$dinitrobenzoic acid
$IV.$ $4-$methoxybenzoic acid

How many of the following compounds react with $NaHCO_3$ to evolve $CO_2$ gas?
$I$: $3$-Nitrophenol
$II$: $2,4$-Dinitrophenol
$III$: $4$-Hydroxybenzoic acid
$IV$: $4$-Methylbenzoic acid
$V$: $4$-Chlorophenol
$VI$: $2,4$-Dinitrotoluene
$VII$: $4$-Hydroxybenzenesulfonic acid
$VIII$: $4$-Sulfobenzoic acid
$IX$: Squaric acid
$X$: Maleic acid

Propionic acid is subjected to reduction with hydroiodic acid in the presence of a little $P$,the product formed is

Aspirin can be prepared by reacting salicylic acid with

Identify $A$ and $B$ in the following reaction:
$CH_3-CH_3 \stackrel{B}{\longleftarrow} CH_3COOH \stackrel{A}{\longrightarrow} CH_3CH_2OH$
$A \quad B$

Which of the following esters,after reduction with $LiAlH_4$ followed by aqueous workup,will yield two molecules of only a single alcohol?