For the formation of $\mathrm{NH}_3(g)$ from its constituent elements, the favourable conditions for its…
For the formation of $\mathrm{NH}_3(g)$ from its constituent elements, the favourable conditions for its formation are
high pressure and low temperature
high pressure and high temperature
low pressure and high temperature
low pressure and low temperature
Solution
Formation of $\mathrm{NH}_3$ takes place according to Le-Chatelier's principle.
$$
\mathrm{N}_2(g)+3 \mathrm{H}_2(g) \longrightarrow 2 \mathrm{NH}_3(g)
$$
Number of moles of reactant $=1+3=4$
Number of moles of product $=2$
As number of moles of product is less than number of moles of reactants.
So, increase in pressure will favour forward direction.
As $\mathrm{NH}_3$ is a gas, so decrease in temperature will favour forward direction.
Hence, high pressure and low temperature are favourable conditions for formation of $\mathrm{NH}_3$.