Question

Which of the following statements about catalysts is false? A catalyst provides a different reaction pathway with a lower activation energy. A catalyst cannot affect the overall energy change for the reaction. A catalyst speeds up both the forward and reverse reactions. A catalyst is present before the reaction begins, and is also present in the same form after the reaction ends. A catalyst stabilizes the product of the reaction relative to the reactant.

Answer 1

The false statement is that a catalyst stabilizes the product of the reaction relative to the reactant. Catalysts reduce activation energy and increase reaction speed but do not change the overall energy change or stabilize the products relative to the reactants.

Step-by-step explanation:

The false statement about catalysts is: A catalyst stabilizes the product of the reaction relative to the reactant. A catalyst provides a different reaction pathway with a lower activation energy but does not affect the overall energy change for the reaction, nor does it stabilize the products relative to the reactants.

It simply allows the reaction to achieve equilibrium faster by speeding up both the forward and reverse reactions without being consumed in the process.

Answer 2

The false statement is: A catalyst stabilizes the product of the reaction relative to the reactant.

Step-by-step explanation:

We can answer this question by looking at a plot of Energy vs. Reaction Progress (attached) for a reaction without a catalyst (black line) and the same reaction with a catalyst (orange line).

• A catalyst provides a different reaction pathway with a lower activation energy. TRUE. The catalyzed reaction has a transition state with a lower activation energy.

• A catalyst cannot affect the overall energy change for the reaction. TRUE. The overall energy change (ΔH) is the same in both cases.

• A catalyst speeds up both the forward and reverse reactions. TRUE. This is the reason why catalysts do not affect the equilibrium. They increase direct and inverse reaction rates.

• A catalyst is present before the reaction begins, and is also present in the same form after the reaction ends. TRUE. This is a key difference between reactants and catalysts. Catalysts can be recovered unaltered at the end of the reaction.

• A catalyst stabilizes the product of the reaction relative to the reactant. FALSE. A catalyst stabilizes the transition state by decreasing the activation energy.