For the reaction , the concentrations of A and B are equal. The equilibrium concentration of C is twice that of A. KC of the reaction is

Let initial moles of A = Initial moles of B = 1According to the equaiton.For every one mole of A One mole of B reacts and one mole each of C and D are form.Let 'x' moles of 'A' react.Givenx = 2(1 - x)