Which of the following describes any reaction that has attained chemical equilibrium?
a. the concentration of the reactants equals the concentration of the products.
b. the rate of the forward reaction is equal to the rate of the reverse reaction.
c. all of the reactants have been converted to the products of the reaction.
d. all of the products have been converted to the reactants of the reaction.
e. both the forward and the reverse reactions have stopped with no net effect on the concentration of the reactants and the products.