Measuring rates of reaction: Practice Questions

Which statement correctly describes the role of a catalyst in a chemical reaction?

A student investigates the rate of reaction between marble chips and hydrochloric acid. The student measures the volume of gas produced over time. Which of the following changes would increase the frequency of collisions between reactant particles and also increase the proportion of particles with energy greater than the activation energy?

A reaction is at dynamic equilibrium in a closed system:
\(PCl_{3}(g) + Cl_{2}(g) \rightleftharpoons PCl_{5}(g)\) (The forward reaction is exothermic)

Which set of conditions would shift the position of equilibrium to the right to increase the yield of \(PCl_{5}\)?

A student is investigating the rate of reaction between marble chips (calcium carbonate) and dilute hydrochloric acid. Which of the following changes would decrease the rate of this reaction?

A sample of magnesium is reacted with excess sulfuric acid. The volume of hydrogen gas produced is measured over time. If the experiment is repeated using the same mass of magnesium but in powdered form instead of a single ribbon, how will the initial rate and the final volume of gas change?

State the term used to describe a substance that increases the rate of a chemical reaction but remains chemically unchanged and has the same mass at the end of the reaction.