Identify substrate 'S' in the following reaction.
$\text{S} \xrightarrow{\large{\text{Na / dry ether}}}$ 3, 4 - diethyl - 3, 4 - dimethyl hexane

Select the correct decreasing order of acid strength for the following compounds.
a) Ethanol   b) 2-Methyl propan-2-ol   c) Phenol   d) p - Nitrophenol

Which of the following isomers of $\text{C}_4\text{H}_9\text{OH}$ has lowest boiling point ?

Identify the 'product' in the following reaction.
Pent - 3 - enenitrile $\xrightarrow[\large{\text{H}_3\text{O}^+}]{\large{\text{Al H (i-Bu)}_2}}$ Product