When zinc reacts with hydrochloric acid, it produces hydrogen gas. As the reaction proceeds, why does the rate of production of
hydrogen gas decrease? a. The concentration of hydrogen gas decreases.
b. The concentration of the reactants decreases.
c. The hydrogen gas formed inhibits the reaction.
d. The hydrogen gas also reacts with the zinc metal.
Answer: b. The concentration of the reactants decreases.
Explanation: Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
k= rate constant
x = order with respect to
y = order with respect to
Thus when concentration of reactants decrease, the rate of the reaction decreases.