Chemical EquilibriaMedium
Le Châtelier's principle
For N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ΔH = -92 kJ.
Predict the effect of: (a) increasing [N₂], (b) increasing P, (c) increasing T.
Predict the effect of: (a) increasing [N₂], (b) increasing P, (c) increasing T.
Given data
ΔH = -92 kJ (exothermic)Δn = 2 - (1+3) = -2 (gas moles decrease)- (a) What happens when [N₂] increases?
- (b) What happens when total pressure increases?
- (c) What happens when temperature increases?
Full worked solution
- (a) What happens when [N₂] increases?Equilibrium shifts right (toward products).
- (b) What happens when total pressure increases?Equilibrium shifts right (2 mol vs 4 mol).
- (c) What happens when temperature increases?Equilibrium shifts left (toward reactants).
Result:(a) ↑[N₂] → right — (b) ↑P → right — (c) ↑T → left.