Which Statement Describes A Catalyst

Question: Which statement best describes the use of a catalyst in a fuel cell?

Answer: It increases reaction rates.

Question: Why does platinum metal make a good catalytic surface for reactant molecules?

Answer: It holds reactant molecules in a good position for them to react

Question: Hydrogen gas reacts rapidly with oxygen gas in the presence of a platinum catalyst. Which equation correctly represents this reaction?

Answer: 2H2 (g) + O2 (g) ----Pt----> 2H2O (g)

Question: Which of the following statements describes how enzymes differ from ordinary chemical catalysts?

Answer: Enzymes catalyze select chemical reactions

Question: Which statement defines enzymatic activity?

Answer: Enzymes regulate cellular functions through feedback mechanisms.

Question: Which statement describes a homogeneous catalyst?

Answer: It is in the same phase as the reactants.

Question: Which statement defines activation energy?

Answer: It is the difference between reactant energy and maximum energy.

Question: Pepsin is a water-soluble enzyme that helps digest proteins in the human stomach. A chemist dissolves a protein in water in a test tube and then mixes a small amount of powdered pepsin into the protein solution to break the protein down. How would pepsin most likely be categorized?

Answer: It is a homogeneous catalyst because both the reactant and the enzyme are liquids.

Question: What overall effect does adding a catalyst have on a chemical reaction?

Answer: It lowers the activation energy that is needed.

Question: Which statement describes a catalyst?

Answer: Catalysts provide a lower energy pathway for the reaction.