1. How does catalysis work? a. It speeds up a reaction by lowering the Gibbs fre

ID: 832603 • Letter: 1

Question

1. How does catalysis work?

a. It speeds up a reaction by lowering the Gibbs free energy of activation.

b. It speeds up a reaction by lowering the Gibbs free energy of the chemical reaction.

c. It speeds up a reaction by stabilizing the reaction-activated complex.

2. The difference between homo- and heterogeneous catalysts is that:

a. Homogeneous catalysts are present in the same phase with the products; heterogeneous ones are not.

b. Homogeneous catalysis are well mixed (homogenized), while heterogeneous catalysts are not.

c. Homogeneous catalysts are present in the same phase with the reagents; heterogeneous ones are not.

3. Which of the following constitute genuine examples of catalysis and which do not? Justify your answer.

(a) The addition of H2 to C2H4 when the mixture is brought into contact with finely divided platinum.

(b) The reaction of an H2/O2 gas mixture when an electrical arc is struck.

1 - (a)

2- (c)

3- a: example of cataysis because platinum will just provide the surface and is not being consumed in the reaction.

b: not an example of catalysis because the electric arc is being consumed in the reaction and a catalyst is never consumed in a reaction.

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.