Which is true about reaction rates? a. high reaction rates occur only in spontaneous reactions. b. low reaction rates occur only in nonspontaneous reactions. c. reaction rates are not dependent on high or low activation energies. d. reaction rates are not related to spontaneity.

 D. Reaction rates are not related to spontaneity.

Explanation: A spontaneous reaction is one which occurs on its own or on some activation.

Non spontaneous reactions are those which do not occur on their own and thus constant energy must be supplied to make them happen.

Reaction rate is dependent on the amount of reactants and the activation energy and not on the spontaneity of the reaction.

Reactions with high activation energy are slow and reactions with low activation energy are fast.