Concept:The Haber process for synthesizing ammonia is a classic application of Le Chatelier's Principle regarding temperature and pressure manipulation.
Formula:$$ \text{N}_{2(g)} + 3\text{H}_{2(g)} \rightleftharpoons 2\text{NH}_{3(g)} \quad \Delta H = -92.4 \text{ kJ/mol} $$
Solution:- Temperature: The forward reaction is exothermic. Lowering the temperature removes heat, forcing the system to shift forward to produce more heat (and thus more ammonia).
- Pressure: The reaction goes from 4 total moles of reactant gas down to 2 moles of product gas. Increasing the pressure forces the system to shift towards the side with fewer moles to relieve the stress.
- Combining these, Low temperature and high pressure mathematically guarantee the highest theoretical yield.
Why other options are incorrect:High temperature shifts the reaction backwards. Low pressure shifts the reaction backwards.
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