Question

Which of the following would increase the rate of a chemical reaction between hydrochloric acid (HCl) and solid zinc metal (Zn)?
Question 1 options:

A)

Performing the reaction at a lower temperature

B)

Decreasing the amount of Zn

C)

Pulverizing the zinc metal into a fine powder

D)

Decreasing the concentration of HCl

Answer 1

To increase the rate of a chemical reaction, we typically look for factors that enhance collisions between reactants. Let's analyze each option:

A) **Performing the reaction at a lower temperature** - Lowering the temperature generally decreases the kinetic energy of the molecules, leading to fewer effective collisions and a slower reaction rate. This would not increase the reaction rate.

B) **Decreasing the amount of Zn** - Reducing the amount of zinc available would decrease the number of reactant particles that can collide with HCl, which would likely decrease the reaction rate rather than increase it.

C) **Pulverizing the zinc metal into a fine powder** - By increasing the surface area of the zinc, powdered zinc will have more exposure to hydrochloric acid, allowing for more collisions and therefore increasing the reaction rate. This is a valid choice for increasing the rate of reaction.

D) **Decreasing the concentration of HCl** - A lower concentration of HCl means there are fewer HCl molecules available to collide with the zinc, which would lead to a decrease in the reaction rate.

Based on this analysis, the correct answer is:

**C) Pulverizing the zinc metal into a fine powder**