Which of the following statements is true regarding catalysts?
A) They are consumed in the reaction
B) They increase the activation energy of the reaction.
C) They provide an alternative pathway with a lower activation energy.
D) They shift the position of equilibrium in a reversible reaction,
The correct answer and explanation is:
The correct answer is C) They provide an alternative pathway with a lower activation energy.
Explanation:
Catalysts are substances that increase the rate of a chemical reaction without being consumed in the process. They achieve this by providing an alternative reaction pathway that requires less energy to reach the transition state, which lowers the activation energy. The activation energy is the minimum energy required for reactants to undergo a reaction. By lowering this energy threshold, catalysts allow the reaction to proceed more quickly and efficiently.
Catalysts do not alter the equilibrium of a reversible reaction. While they speed up the rate at which equilibrium is reached, they do not affect the position of the equilibrium. This means that, even though they help reactants convert into products faster, they do not change the relative concentrations of reactants and products once the system has reached equilibrium.
One important characteristic of catalysts is that they are not consumed or changed permanently during the reaction. After facilitating the reaction, the catalyst remains unchanged and can be used again in subsequent reactions. This is why only a small amount of catalyst is needed to catalyze a large number of reactions.
In contrast, A) They are consumed in the reaction is incorrect because catalysts are not consumed during the reaction. B) They increase the activation energy of the reaction is also false because catalysts lower the activation energy. Lastly, D) They shift the position of equilibrium in a reversible reaction is incorrect because catalysts do not affect the equilibrium position, they only affect how quickly equilibrium is reached.
In summary, the primary role of a catalyst is to provide a faster route for the reaction to proceed by lowering the activation energy, without affecting the equilibrium or being consumed in the process.