Question

Which choice below would affect best, the rate of reaction?

• A. Cool the reaction down
• B. Add a catalyst
• C. Decrease the pressure
• D. Use larger pieces of solid reactants
• E. Decrease the concentration of the reactants

Answer 1

Answer: (B)

Add a catalyst

$\bullet$ Lowering the temperature will decrease the value of the rate constant.

$\Rightarrow$ rate of reaction will decrease.

$\bullet$ Adding a catalyst will increase the rate of the reaction.

$\Rightarrow$ rate of reaction will increase.

$\bullet$ Decreasing pressure will indirectly affect the rate of reaction as concentration would decrease.

$\Rightarrow$ rate of reaction will decrease.

$\bullet$ Using larger pieces of solid reactants will decrease the number of collisions and hence affect rate.

$\Rightarrow$ rate of reaction will decrease.

$\bullet$ Decreasing the concentration of reactants will decrease the rate.

$\Rightarrow$ rate of reaction will decrease.

Hence, adding a catalyst is the best one out of given options.