Define restricted rotation and give one example each of acyclic and cyclic compounds, which can show geometrical isomerism.

Which of the following can show geometrical isomerism.

$\left(\mathrm{i}\right)$

$\left(\mathrm{ii}\right)$ 

$\left(\mathrm{iii}\right)$ 

$\left(\mathrm{iv}\right)$ 

$\left(\mathrm{v}\right)$ 

$\left(\mathrm{vi}\right)$

$\left(\mathrm{vii}\right)$ 

$\left(\mathrm{viii}\right)$ ${\mathrm{CH}}_2=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}-\mathrm{Ph}$

Which of the following carbonyl compound will give two products after reaction with ${\mathrm{NH}}_2\mathrm{OH}$ ?

(i) $\left(\mathrm{ii}\right)$ ${\mathrm{CH}}_3-\mathrm{CHO}$   $\left(\mathrm{iv}\right)$ $\text{DCHO}$ 

The total number of fractions ($n$) obtained in the following reaction is

Number of chiral carbon present in the following compound: