11.3 Factors Affecting Chemical Equilibrium
1) Effect of change of concentration
By increasing or decreasing the concentration of one of the reactants or products, the reaction can be manipulated in the desired direction.
To increase the yield of NH3 the concentration of N2 or preferably H2 should be increased in the synthesis of ammonia.
2) Effect of change of pressure
Reactions which proceed with decrease in volume are favored by high pressures.
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On the other hand, reactions which proceed with increase in volume are favored by low pressures.
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If the volume remains the same then change in pressure has no effect.
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3) Effect of change in temperature
Exothermic reactions will be favored by decrease in temperature
Endothermic reactions will be favored by increase in temperature.
4) Effect of catalyst
The presence of a catalyst in a reversible reaction does not affect the state of equilibrium but only causes the reaction system to attain equilibrium in a shorter period of time.