The synthesis of ammonia, 3 H2(g) + N2(g) ⇌ 2 NH3(g), ΔH° = –92 kJ mol⁻¹
CHEMISTRY · Subjective · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
The synthesis of ammonia,
3 H2(g) + N2(g) ⇌ 2 NH3(g), ΔH° = –92 kJ mol⁻¹,
is at equilibrium at 400 K when the temperature is altered as described below; all other conditions remain constant.
(i) Temperature is raised by 30 K.
(ii) Temperature is raised by 10 K.
(iii) Temperature is lowered by 15 K.
Rank the trials from greatest to least in terms of the extent of the shift toward decomposition of NH3 that will occur as new equilibrium is established.