Question

State one relevant observation when ammonia gas is burnt in an atmosphere of excess oxygen.

Answer 1

When ammonia gas is burnt in an atmosphere of excess oxygen it burns with a yellowish-green flame due to the formation of nitrogen gas.

The chemical reaction involved:

$\underset{\mathrm{Gas}}{\underset{\mathrm{Ammonia}}{4{\mathrm{NH}}_3\left(\mathrm{g}\right)}}+\underset{\mathrm{Gas}}{\underset{\mathrm{Oxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}}\to \underset{\mathrm{Gas}}{\underset{\mathrm{Nitrogen}}{2{\mathrm{N}}_2\left(\mathrm{g}\right)}}+\underset{\mathrm{Vapor}}{\underset{\mathrm{Water}}{6{\mathrm{H}}_2\mathrm{O}(\mathrm{g}}})$