Explain the effect of temperature on reaction rate and the role of a catalyst, referencing Investigations I and II.

Here are the solutions to Investigation II and III.

5.2 Investigation II

When the investigation is repeated at $30^\circ \text{C}$ with the same reactants and catalyst, compared to Investigation I:

• 5.2.1 The size of the shaded area (diagram B) A decrease in temperature (assuming Investigation I was at a higher temperature) means that the average kinetic energy of the particles decreases. Consequently, fewer particles will possess kinetic energy equal to or greater than the activation energy. The size of the shaded area DECREASES.

• 5.2.2 The value of Y The value of Y represents the activation energy of the catalyzed reaction. A catalyst lowers the activation energy. Since the *same