What is the required practical for investigating temperature changes?

The required practical for investigating temperature changes involves carrying out an exothermic or endothermic reaction and measuring the temperature change.

In this practical, you will be investigating how the temperature changes during a chemical reaction, specifically an exothermic or endothermic reaction. An exothermic reaction is one that releases heat into the surroundings, causing the temperature to rise. On the other hand, an endothermic reaction absorbs heat from the surroundings, causing the temperature to drop.

To carry out this practical, you will need a thermometer, a polystyrene cup (to act as a calorimeter), a measuring cylinder, and the chemicals for the reaction. The chemicals could be a combination of an acid and a base, or a metal and an acid, depending on the reaction you are investigating.

First, measure a fixed volume of the first reactant using the measuring cylinder and pour it into the polystyrene cup. Then, measure the initial temperature using the thermometer. After that, add the second reactant and quickly stir the mixture while measuring the temperature at regular intervals. Record the highest or lowest temperature reached, depending on whether it's an exothermic or endothermic reaction.

The temperature change can then be used to calculate the enthalpy change for the reaction using the formula: ΔH = mcΔT, where m is the mass of the reactants, c is the specific heat capacity, and ΔT is the change in temperature.

Remember to always handle chemicals with care and wear appropriate safety gear, such as gloves and goggles, during the experiment. This practical will help you understand the energy changes that occur during chemical reactions, a key concept in GCSE Chemistry.