The van't hoff factor can be expressed as the ratio of
(i) normal molar mass to that of abnormal molar mass
(ii) Observed colligative to that of calculated colligative property
(iii) Total number of moles of particles after association// dissociation to that of total number of moles of particles before association//dissociation
(iv) Observed molality to that of calculate molality

Options

A. (i), (ii), (iii)
B. (i), (ii), (iii), (iv)
C. (ii), (iv)
D. (i). (ii)

Answer

1

Explanation

Abnormal molar masses were first noticed by van't hoff who introduced on empirical factor, I, known as van't hoff factor. It is used to ascertain whether the solute associates or dissociates in a given solvent and also to ascertain the extent of association or dissociation. It also helps to get the right molecular mass.
It is usually defined as ratio of observed solligative property to that of calculated colligative property (or the ratio of the freezing point depression of an electroyte to that of a nonelectrolyte). But it can be defined in terms of molar mass, molality or number of moles of particles.