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Exothermic reactions transfer energy to the surroundings and the temperature of the surroundings increases. Endothermic reactions take in energy and the temperature of the surroundings decreases.

A chemical cell produces a voltage until one of the reactants is used up. In a hydrogen-oxygen fuel cell, hydrogen and oxygen are used to produce a voltage, and water is the only product.

Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.