How can we increase the rate of collisions between the reactants in this reaction? mg + 2hcl → mgcl2 + h2 a. increase the concentration of h2 in the reaction mixture. b. decrease the temperature of the reactants in the reaction mixture. c. increase the concentration of mg in the reaction mixture. d. decrease the temperature of the entire reaction mixture. e. decrease the concentration of hcl in the reaction mixture.

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.

the molecules move in straight line until they collide with each other or with the walls of the container. collisions are perfectly elastic; when two molecules collide, they change their directions and kinetic energies, but the total kinetic energy is conserved.

explanation: