Describe the favorable conditions for the manufacture of ammonia by Haber's process.

Arrange the following in order of increasing basic strength : ${\mathrm{BiH}}_3, {\mathrm{SbH}}_3, {\mathrm{PH}}_3, {\mathrm{NH}}_3, {\mathrm{AsH}}_3$.

The following are some statements related to $\mathrm{VA}$ group hydrides.

$\mathrm{I}.$ Reducing property increases from ${\mathrm{NH}}_{3 }\mathrm{to} {\mathrm{BiH}}_3$

$\mathrm{II}.$ Tendency to donate lone pair decreases from ${\mathrm{NH}}_3 \mathrm{to} {\mathrm{BiH}}_3$

$\mathrm{III}.$ Thermal stability of hydrides decreases from ${\mathrm{NH}}_{3 }\mathrm{to} {\mathrm{BiH}}_3$

$\mathrm{IV}.$ Bond angle of hydrides decreases from ${\mathrm{NH}}_3 \mathrm{to} {\mathrm{BiH}}_3$

The correct statements are