(13)

where (V_MW) is the molar volume of the methanol/water associate.

Now, the weight of the water in the solvent mixture (w_W) will be given by,

(14)

Similarly, the weight of the methanol in the solvent mixture (w_M) will be

(15)

and, finally, the weight of the methanol/water associate in the solvent mixture (w_MW) will be

(16)