4.17 Affects of temperature, pressure and conc. on equilibrium

Question 1

Effect of changing concentration

Answer 1

If the concentration of one of the reactants or products is changed, the system is no longer at equilibrium and the concentrations of the substances will change until it is at equilibrium again.

If concentration of reactants is increased, the position of equilibrium shifts towards products so more product is produced until it is at equilibrium.

If concentration of products is increased, more reactant is produced until it is at equilibrium.

Question 2

Effect of changing pressure

Answer 2

In reactions of gases, an increase in pressure will favour the reaction that produces the least number of molecules.

If a reaction produces a larger volume of gas, the equilibrium will shift left if there is an increase in pressure. If there is a decrease in pressure, the equilibrium will shift right.

If a reaction produces a smaller volume of gas, the equilibrium will shift right if there is an increase in pressure. If there is a decrease in pressure, the equilibrium will shift left.

Question 3

Effect of temperature

Answer 3

If temperature is increased, equilibrium moves in the direction of the endothermic reaction

If temperature is decreased, equilibrium moves in the direction of the exothermic reaction