Decomposition of ammonia (\(\text{NH}_3\)) into nitrogen (\(\text{N}_2\)) and hydrogen (\(\text{H}_2\))

Overall reaction: 
\( 2 \text{NH}_3 (g) \rightarrow \text{N}_2 (g) + 3 \text{H}_2 (g) \)

Mechanism

Step 01: Surface Reaction Mechanism
\( 2 \text{NH}_3 \text{ (adsorbed on catalyst surface)} \rightarrow \text{N}_2 \text{ (adsorbed on surface)} + 3 \text{H}_2 \text{ (adsorbed on surface)} \) (slow)

Step 02: Desorption
 \(  \text{N}_2 \text{ (desorbs)} + 3 \text{H}_2 \text{ (desorbs)} \) (fast)

Rate Law:
\( \text{Rate} = k  \)

Note : On a hot tungsten wire at relatively high pressure