The relation between Vant Hoff factor (1) and the degree of dissociation ( α ) for a weak electrolite given by formula AxBy is:
α=i−1x+y−1
AxBy → xA + yBInitial Conc.: C 0 0final Conc: C(1−α) xCα yCαNow, i=C(1−α)+xCα+yCαCα=1−α+xα+yα∴α=i−1(x+y−1)