Question

Which of the following are true statements with regard to catalyst?

a. A catalyst is formed in the first elementary step of a reaction and consumed by a later step.

b. Catalysts can speed up chemical reactions by providing the reactants with more
energy.

c. Catalysts can speed up chemical reactions by providing an alternate pathway for the reaction that requires less energy.

d. Catalysts can speed up chemical reactions by providing an alternate pathway for the reaction that requires more energy.

e. Catalysts can speed up a chemical reaction by increasing the number of collisions.

f. Catalysts can speed up chemical reactions by forming intermediates and introducing new elementary steps that require less energy.

g. Catalysts are completely consumed in the reaction.

h. Catalysts are regenerated within a chemical reaction.

Answer 1

A catalyst is a substance that increases the speed of a reaction without being consumed. It provides an alternate pathway for the reaction that requires less energy.

Step-by-step explanation:

A catalyst is a substance that increases the speed of a reaction without being consumed in the process. It does this by providing an alternate pathway for the reaction that requires less energy. Therefore, statement c is true. Statement a is false, as the catalyst is not formed in the first elementary step of a reaction. Statement b is false, as a catalyst does not provide the reactants with more energy. Statement d is false, as a catalyst provides an alternate pathway that requires less energy, not more. Statement e is false, as a catalyst does not increase the number of collisions, but rather lowers the activation energy. Statement f is false, as a catalyst does not form intermediates or introduce new elementary steps. Statement g is false, as a catalyst is not completely consumed in the reaction. Statement h is true, as a catalyst can be regenerated within a chemical reaction.

Answer 2

A: False, because the catalyst appears in the reactant and product in the main reaction, it will not appear in the product in the main reaction in this case

B: False, Catalysts speed up reaction by providing an alternative pathway for the reaction which have lower activation energy

C: True

D: False, Higher activation energy results in a slower reaction

E: False, it only provide an alternative pathway and do nothing with collisions

F: True

G: False, as I said before, catalyst does appears on the product and reactant side on the main reaction

H: True