<P> Similarly, if a fraction α (\ displaystyle \ alpha) of n (\ displaystyle n) moles of solute associate to form one mole of an n - mer (dimer, trimer, etc .), then </P> <Dl> <Dd> i = 1 − (1 − 1 n) α . (\ displaystyle i = 1 - \ left (1 - (\ frac (1) (n)) \ right) \ alpha .) </Dd> </Dl> <Dd> i = 1 − (1 − 1 n) α . (\ displaystyle i = 1 - \ left (1 - (\ frac (1) (n)) \ right) \ alpha .) </Dd> <P> For the dimerisation of acetic acid in benzene </P>

Van't hoff factor more than unity indicates that the solute in solution has