HESI A10
HESI A2 Chemistry Practice Test
1. Which of the following lists four factors that affect rates of reaction?
- A. Barometric pressure, particle size, concentration, and the presence of a facilitator
- B. Temperature, particle size, concentration, and the presence of a catalyst
- C. Temperature, container material, elevation, and the presence of instability
- D. Volatility, particle size, concentration, and the presence of a catalyst
Correct answer: B
Rationale: The correct answer is B. The factors that influence rates of reaction are temperature, particle size, concentration, and the presence of a catalyst. Temperature affects the speed of molecules, particle size impacts the available surface area for reactions, concentration influences the collision frequency between reactant molecules, and catalysts accelerate reactions by providing an alternative pathway with lower activation energy. Choices A, C, and D are incorrect as they either include irrelevant factors that do not affect reaction rates (barometric pressure, container material, elevation, and volatility) or lack important factors that do influence reaction rates (like a catalyst).