Higher yield of NO in
N₂(g) + O₂ → 2NO(g) can be obtained at
[ΔH of the reaction = +180.7 kJ mol⁻¹]

A. higher temperature

B. lower temperature

C. higher concentration of N₂

D. higher concentration of O₂

Choose the correct answer from the options given below:

CONCEPT:

Effect of Temperature and Concentration on Chemical Equilibrium

• The given reaction is:

  N₂(g) + O₂(g) → 2NO(g)

• This reaction is endothermic because ΔH = +180.7 kJ mol⁻¹.
• According to Le Chatelier's Principle:
  • For an endothermic reaction (ΔH > 0), increasing the temperature shifts the equilibrium toward the products (higher yield of NO).
  • Increasing the concentration of reactants (N₂ and O₂) also shifts the equilibrium toward the products, increasing the yield of NO.

EXPLANATION:

• Higher temperature: Since the reaction is endothermic, increasing the temperature supplies more energy to drive the reaction forward.
• Higher concentration of N₂: Adding more N₂ shifts the equilibrium toward the products.
• Higher concentration of O₂: Adding more O₂ also shifts the equilibrium toward the products.

Therefore, the correct answer is A, C, D only.