DEFINITION AND CLASSIFICATION OF
COLLOIDS

Number average relative molecular mass (= Number average molecular weight)		$\bar{M}_{r,n}$
$[\bar{M}_{r,n} = \frac{{\sum}n_i M_r(i)}{{\sum}n_i}]$
Mass average relative molecular mass (= Mass average molecular weight)		$\bar{M}_{r,m}$
$[\bar{M}_{r,m} = \frac{{\sum}n_i \left(M_r(i)\right)^2}{{\sum}n_iM_r(i)}]$
Z-average relative molecular mass (= Z-average molecular weight)		$\bar{M}_{r,Z}$
$[\bar{M}_{r,Z} = \frac{{\sum}n_i \left(M_r(i)\right)^3}{{\sum}n_i\left(M_r(i)\right)^2}]$