2.9b: deduce the qualitative effects of changes of temperature, pressure and concentration on the position of equilibrium, eg extraction of methane from methane hydrate

TEMPERATURE

Decreasing the temperature of a system at equilibrium will shift equilibrium to the side of the exothermic reaction, as the system works to increase the temperature

Increasing the temperature of a system at equilibrium will shift equilibrium to the side of the endothermic reaction, as the system works to reduce the temperature

PRESSURE

If we increase the pressure of a system at equilibrium, the equilibrium will shift to the side of the reaction with fewer gaseous molecules, in an attempt to reduce the pressure

CONCENTRATION

Increasing the concentration of a reactant will increase the rate of the forward reaction, increasing the yield of product

Decreasing the concentration of a reactant will decrease the rate of the forward reaction, decreasing the yield of product

CATALYST

Adding a catalyst does not affect the position of equilibrium, as it increases the rate of the forward and backward reactions equally

• equilibrium is reached more quickly