Mention the conditions required to maximise the yield of ammonia.

Explanation

Ammonia is prepared by the Haber's process.
`{:(," "700 K", "200 xx 10^(5) Pa,),(,"Iron oxide " +K_(2)O + Al_(2)O_(3)"(catalyst)",),(N_(2) (g) + 3H_(2) (g),overset("Mo (promoter)")(hArr),2 NH_(3)(g),Delta_(f)H^(@)=-92.4 kJ mol^(-1)):}`
In accordance with Le Chatelier's principle, to maximize the yield, a high pressure of 200 `xx 10^(5)` Pa is used. To increase the rate of the reaction, a temperature of around 700 K is usd and iron oxide mixed with some `K_(2)O and Al_(2)O_(3)` is used as a catalyst. Sometimes, Mo is also used as a promoter to increase the efficiency of the Fe catalyst.