Answer. The reaction mixture does not have 50% reactants and 50% products at equilibrium state because concentration of reactants and products depends upon the numerical value of Kc. If the numerical value of Kc is large at equilibrium state reactants are almost negligible and the products are present in large concentration. On the other hand, if the numerical value Kc is small; at equilibrium state products are almost negligible and reactants are present in large concentration. However, if the numerical value of Kc is neither large nor small, concentrations of reactants and products are comparable.