Statement-I : Ammonolysis of excess alkylhalide  in a sealed tube at 373 K is the best method to prepare 1° amines.

Statement-II : Excess ammonia with alkyl halide at 373 K gives 1° amine as major product 

I) Ammonolysis of alkyl halide gives a mixture of 1° amine, 2° amine, 3° amine and a 4° salt. This mixture is difficult to separate. This is not a suitable method to prepare 1° amine.

$\underset{\left(\mathrm{Excess}\right)}{\mathrm{R}-\mathrm{X}}\underset{-\mathrm{HX}}{\overset{{\mathrm{NH}}_3}{\to }}\mathrm{R}-{\mathrm{NH}}_2\underset{-\mathrm{HX}}{\overset{\mathrm{R}-\mathrm{X}}{\to }}{\mathrm{R}}_2\mathrm{NH}\underset{-\mathrm{HX}}{\overset{\mathrm{R}-\mathrm{X}}{\to }}{\mathrm{R}}_3\mathrm{N}\underset{ }{\overset{\mathrm{RX}}{\to }}{\mathrm{R}}_4{\mathrm{N}}^{+}{\mathrm{X}}^{-};$

$\mathrm{II})\hspace{0.17em} \mathrm{R}-\mathrm{X}+{\mathrm{NH}}_3\left(\mathrm{excess}\right)\to \underset{\mathrm{major}}{\mathrm{R}-{\mathrm{NH}}_2}+\mathrm{HX}$