Which two factors must be equal when a chemical reaction reaches equilibrium?
(1) the concentration of the reactants and the concentration of the products
(2) the number of reactant particles and the number of product particles
(3) the rate of the forward reaction and the rate of the reverse reaction
(4) the mass of the reactants and the mass of the products
The correct answer is option 3. Equilibrium is achieved in a chemical reaction when the rate of the forward reaction is the same for the rate of the backward reaction and when the reaction has stopped.
