Question

How can we increase the rate of collisions between the reactants in this reaction?

Answer 1

Decreasing temperature will lower reaction rate which rules out B and D.

Increasing H2, a reaction product, or decreasing HCL, a reactant, will lower reaction rate too. So A and E is out.

The right answer is C.  Increase the concentration of Mg in the reaction mixture.

Answer 2

Answer: Option (C) is the correct answer.

Explanation:

According to collision theory, more is the number of collision between the reactant molecules more will be the rate of reaction.

For example, $Mg + 2HCl \rightarrow MgCl_{2} + H_{2}$

When we increase the concentration of reactants then it means there is increase in number of molecules. Hence, more is the number of molecules more will be the number of collisions.

Thus, we can conclude that by increasing the concentration of Mg in the reaction mixture we increase the rate of collisions between the reactants in this reaction.