IGCSE Chemistry Edexcel 4CH1

know that some reactions are reversible and this is indicated by the symbol ⇌ in equations

describe reversible reactions such as the dehydration of hydrated copper (II) sulfate and the effect of heat on ammonium chloride

know that a reversible reaction can reach dynamic equilibrium in a sealed container

know that the characteristics of a reaction at dynamic equilibrium are:

• the forward and reverse reactions occur at the same rate
• the concentrations of reactants and products remain constant.

understand why a catalyst does not affect the position of equilibrium in a reversible reaction

know the effect of changing either temperature or pressure on the position of equilibrium in a reversible reaction:

• an increase (or decrease) in temperature shifts the position of equilibrium in the direction of the endothermic (or exothermic) reaction
• an increase (or decrease) in pressure shifts the position of equilibrium in the direction that produces fewer (or more) moles of gas

References to Le Chatelier's principle are not required