Define the following terms:
(i) Colligative properties (ii) Molality (m)

Explanation

(i) Colligative properties: Those properties of ideal solution which depend only on the number of particles of the solute dissolved in a definite amount of the solvent and do not depend on the nature of solute. For example, (i) Elevation in boiling point (ii) Osmotic pressure (iii) Depression in freezing point.
(ii) Molality (m): It is defined as the numbers of moles of the solute dissolved in 1000 grams (1kg) of the solvent
`{:("Molality (m)" = (n_(B))/(w_(A) (kg)),n_(B) rarr "Moles of solute"),(,w_(A)rarr"Mass of solvent"):}`