Formic acid and acetic acid can be distinguished by

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

Which of the following does not give alcohol on reduction?

Arrange the following compounds in decreasing order of reactivity for the hydrolysis reaction:
$(I) C_6H_5COCl$
$(II) NO_2-C_6H_4-COCl$
$(III) CH_3-C_6H_4-COCl$
$(IV) OHC-C_6H_4-COCl$

When formic acid reacts with $PCl_5$,it forms:

Identify $A, B$ and $C$ in the following reactions:
$CH_3 Cl$ $\xrightarrow{KCN} A$ $\xrightarrow{H_3 O^{\oplus}} B$ $\xrightarrow{C_2 H_5 OH / H^{+}, \Delta} C$