Explain the method of preparation for amine compounds by the reduction of nitro compounds.

(N/A) Reduction of nitro compounds: Nitro compounds are reduced to amines by passing hydrogen gas in the presence of finely divided nickel,palladium,or platinum,and also by reduction with metals in an acidic medium.
Reduction with iron scrap and hydrochloric acid is preferred because the $FeCl_2$ formed gets hydrolysed to release hydrochloric acid during the reaction. Thus,only a small amount of hydrochloric acid is required to initiate the reaction.
Nitroalkanes can also be similarly reduced to the corresponding alkanamines.
$CH_3CH_2NO_2 \xrightarrow[\text{ethanol}]{H_2 / Pd} CH_3CH_2NH_2$
Additionally,nitrobenzene can be reduced to aniline as follows:
$C_6H_5NO_2 \xrightarrow[\text{ethanol}]{H_2 / Pd} C_6H_5NH_2$
$C_6H_5NO_2 \xrightarrow{Sn + HCl \text{ or } Fe + HCl} C_6H_5NH_2$