`NH_(3)` gaws is adsorbed on the metal surface like tungsten This follows …. order kinetics.

Options

A. first
B. third
C. second
D. zero

Answer

D

Explanation

The decomposition of gaseous `NH_(3)` adsorbed on a metal surface is a zero order reaction at high pressure, because the metal surface gets saturated with `NH_(3)` molecules. A further increase in pressure is unable to alter the amount of `NH_(3)` on the surface of the catalyst making reaction rate independent of its concentration.
`2NH_(3)(g)rarrN_(2)(g)+3H_(2)(g)`
Rate `=k[NH_(3)]^(0)=k`