Question

For the manufacture of $N{H}_3$ by the following reaction
$N_2+3H_{2}2N{H}_3+21.9kcal$
the favourable conditions are :

• A. low temperature, high pressure and catalyst
• B. high temperature, high pressure and catalyst
• C. high temperature, high pressure and catalyst
• D. low temperature, low pressure and catalyst

Answer 1

Answer: (A)

$\underset{4V}{N_2(g)}+\underset{3V}{3H_2(g)}\rightleftharpoons \underset{2V}{2N{H}_3(g)}+21.9lcal$
The above reaction is exothermic reaction and the moles of reactants are more than moles of products. According to Le-Chatelier's principle, the conditions favourable for formation of $N{H}_3$ are
$\to$ Low temperature
$\to$ High pressure and presence of catalyst