Question

the rate of a reaction increases when a catalyst has been added to the reaction mixture. the catalyst a increases the kinetic energy of the reactants. b decreases the rate of the reverse reaction. c increases the number of collisions between reactants. d alters the enthalpy of reaction. e provides a new mechanism for the reaction.

Explanation:

A catalyst works by providing an alternative reaction mechanism with a lower activation - energy pathway. It does not change the kinetic energy of reactants (A is wrong), does not decrease the rate of the reverse reaction (B is wrong), does not increase the number of collisions between reactants (C is wrong), and does not alter the enthalpy of reaction (D is wrong). It provides a new mechanism for the reaction to proceed.

Answer:

E. provides a new mechanism for the reaction to proceed.