Question

Which of these statements is not true about chemical reaction rates?

The reaction rates can change.

The reaction rates can increase.

The reaction rates can decrease.

The reaction rates are always constant

Answer 1

The reaction rates are not always constant so the last one is not always true

Answer 2

The reaction rates are always constant

Step-by-step explanation:

Reaction rates are normally high at the beginning of the reaction because the reactants are still in high concentrations. Eventually as the reaction continues more of the product is in the reaction vessel disturbing the collisions of the reactant particles. Also the reactants concentration starts to deplete causing the rate of reaction to decrease. So the rate of a reaction cannot be constant.