Le Chatelier's Principle: Temperature Effect on Exothermic Reaction

Steps:

• Identify the reaction as exothermic (ΔH = -92 kJ/mol), treating heat as a product.
• Increasing temperature adds heat, shifting equilibrium left toward reactants to absorb heat.
• This decreases NH₃ yield while increasing N₂ and H₂.
• At the new equilibrium, forward and reverse rates equalize again.

Why D is correct:

• Le Chatelier's principle predicts shift opposing stress; for exothermic forward reaction, higher temperature favors endothermic reverse, reducing product.

Why the others are wrong:

• A: Shift left decreases product, not increases.
• B: At any equilibrium, forward rate equals reverse rate by definition.
• C: Rates are equal at equilibrium, neither greater nor less.

Final answer: D