The correct option is B (i) 0.74 m, (ii) 0.0132
(ii) We know,
p0=Vapour pressure of water at 373 K = 760 mm Hg
Given,
Vapour pressure of solution = ps=750 mm
As the solution is dilute solution of glucose, hence
Molar mass of solvent MA=18 g mol−1
Relative lowering of vapour pressure in dilute form:
p∘−psp∘=xB
Where, xB=mole fraction of solute
⇒xB=760−750760xB=0.0132
(i) Molality =xB×1000(1−xB)×M
Where,
xB=mole fraction of soluteM=Molar mass of solvent=18 g mol−1
Substituting the values, we get,
Molality=0.013×1000(1−0.013)×18 m
Molality=0.741 m