Molecular weight of an element or compound when expressed in g is called its gram molecular weight, gram molecule or mole molecule.
(i) No. of gm molecules or mole molecules = \(\frac{\text{Wt. of substance}}{\text{GMV}}\)
(ii) Wt. of substance in g = No of g molecules x GMW
Avogadro Number (N): The number of carbon atoms present in one gram atom (1 mole atom of C - 12 isotope is called Avogadro' number. One gram atom (12 grams) of C - 12 contains 6.023 x 1023 atoms. Thus the numerical value of Avogadro's number (M) is 6.023 x 1023 per mol.
