Question

For the manufacture of $NH_3$ by the following reaction
$ N_{2}+3H_{2}2NH_{3}+21.9\,kcal $
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}{2NH_3(g)} + 21.9\,lcal$
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 $NH_3$ are
$ \to $ Low temperature
$ \to $ High pressure and presence of catalyst