Question

Which of the following factors would favour the formation of ammonia?

• A. High pressure
• B. Low temperature
• C. High volume
• D. Low pressure

Answer 1

The correct option is A High pressure

According to Le Chatelier's principle, high pressure would favour the formation of $N{H}_3$
$N_2$(g) + 3$H_2${g) $\leftrightharpoons$ $N{H}_3$(g)
The optimum conditions for the production of $N{H}_3$ are pressure of 200 x 10${}^5$ Pa (about 200 atm) and temperature of -700 K.

In the given reaction, the number of moles of reactant is more than the product and according to the ideal gas equation, the pressure is inversely proportional to the number of moles.

Thus, by increasing pressure i.e. at high pressure, the reaction will proceed in a forward direction towards less number of moles. Thus the formation of the ammonia increases.