How is ammonia manufactured industrially?

Ammonia is prepared on a large-scale by the Haber’s process.

$\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \leftrightharpoons 2 \mathrm{NH}_{3}(\mathrm{~g}) \quad \Delta_{\mathrm{f}} \mathrm{H}^{\circ}=-46.1 \mathrm{~kJ} / \mathrm{mol}$

The optimum conditions for manufacturing ammonia are:

(i) Pressure (around 200 × 105 Pa)

(ii) Temperature (700 K)

(iii) Catalyst such as iron oxide with small amounts of Al2O3 and K2O