Which of the following statements is always true? a. the rate law can be determined from the stoichiometric equation. b. the rate of a catalyzed reaction is independent of the concentration of the catalyst. c. the rate for a reaction depends on the concentrations of all the reactants. d. the rate constant is independent of the concentrations of the reacting species. e. exothermic reactions have lower activation energies than endothermic reactions.

d. The rate constant is independent of the concentrations of the reacting species.

Explanation:

According top law of mass action,

The rate of a reaction is directly proportional to product of active concentration of the reactant each raised to the power of their orders (experimentally determined numbers).

Where, k is rate constant

m and n are order

Hence, a is incorrect.

If order is equal to zero, it means that the rate does not depend on the concentration of that reactant which means that c is incorrect.

Rate constant in the expression of the rate law depends only on temperature and thus, d is correct.

Statement e is not always true.

Catalyst is the specie that alters the rate of a reaction which means that b is incorrect.

a is the correct answer