Concept:According to Le Chatelier's Principle, the yield of an exothermic reaction is maximized by removing heat to shift the equilibrium forward.
Formula:$$ \text{N}_2 + 3\text{H}_2 \rightleftharpoons 2\text{NH}_3 \quad \Delta H = -92.4 \text{ kJ/mol} $$
Solution:- The synthesis of ammonia releases heat (exothermic).
- Heat can be conceptually treated as a product on the right side of the equation.
- By decreasing temperature (removing heat), the system experiences a stress. It responds by shifting forward (to the right) to replace the lost heat.
- This forward shift drastically increases the concentration of the actual product, Ammonia.
Why other options are incorrect:Increasing temperature shifts the reaction backwards. Decreasing reactants shifts it backwards. Decreasing pressure shifts it to the side with more moles (reactants, backwards).
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