Question

A student performs a reaction twice. In the second trial, she raises the temperature by 20¨¬C and notices that the reaction takes place more quickly. She concludes that the reaction must be endothermic. Explain why the student is incorrect.

Answer 1

Explanation:

An endothermic reaction is a reaction in which the reactants absorb energy and the energy of products is more than that of reactants.

Whereas an exothermic reaction is a reaction in which the reactants have more energy as compared to products. Hence, there will be release of energy.

Therefore, when temperature is increased by $20^{o}C$ then it means we are providing more energy to the reactants. As a result, there will be release of energy. Hence, the reaction will be exothermic in nature and not endothermic.

Thus, we can conclude that the student is incorrect because the reaction is exothermic and not endothermic.

Answer 2

Answer: She is incorrect to conclude that the reaction is endothermic.

As in the second trial, the temperature has increased by 20 °C , that means the heat has been released and energy is released in exothermic reactions.

Exothermic reactions: The reactions in which the energy of the products is less than the energy of the reactants, and the excess energy is released as heat.

Endothermic reactions: The reactions in which the energy of the products is more than the energy of the reactants, and the excess energy is absorbed as heat.