The amount of copper chloride affects the temperature of the reaction because it is a catalyst. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction. In this case, the copper chloride helps to speed up the reaction between the hydrogen peroxide and the sodium thiosulfate.

The more copper chloride that is added, the faster the reaction will occur. This is because there are more copper ions available to catalyze the reaction. The copper ions help to break down the hydrogen peroxide into water and oxygen gas. The oxygen gas then reacts with the sodium thiosulfate to form sodium sulfate and water.

The amount of copper chloride that is needed to catalyze the reaction depends on the concentration of the hydrogen peroxide and the sodium thiosulfate. If the concentration of the reactants is high, then more copper chloride will be needed. If the concentration of the reactants is low, then less copper chloride will be needed.

It is important to add the correct amount of copper chloride to the reaction. If too much copper chloride is added, the reaction will occur too quickly and the temperature of the reaction will become too high. This can cause the reactants to decompose and the reaction to become dangerous. If too little copper chloride is added, the reaction will occur too slowly and the temperature of the reaction will not increase enough. This will cause the reaction to be incomplete and the reactants will not be fully converted into products.

By carefully controlling the amount of copper chloride that is added to the reaction, it is possible to achieve the desired reaction rate and temperature.