Le Chatelier's Principle for Yield Optimization

Steps:

• Reaction is exothermic (ΔH negative), so lower temperature favors forward reaction by shifting equilibrium right.
• Gaseous moles decrease from 2 to 1, so higher pressure favors products by shifting equilibrium right.
• Temperature affects rate but equilibrium position favors lower T for exothermic reactions.
• Pressure has no temperature interaction, so combine high pressure with low temperature for maximum yield.

Why A is correct:

• High pressure increases yield (fewer moles on product side); 100 °C (lower temperature) favors exothermic forward reaction per Le Chatelier's principle.

Why the others are wrong:

• B: Low pressure decreases yield (more moles on reactant side); 200 °C shifts equilibrium left for exothermic reaction.
• C: High pressure increases yield, but 200 °C shifts equilibrium left, reducing product.
• D: Low pressure decreases yield despite 100 °C favoring forward reaction.

Final answer: A