Question

The density of 2.45 M methanol in its aqueous solution is 0.9766 g/ml The molality of the soultion is :

A 27.3

B 2.73

C 2.45

D 0.273

Answer 1

molar mass CH3OH = 32g.
mass ot 2.45moles = 2.45 x 32 = 78.4g.
mass of solution = 976g.
mass of solvent = 976g - 78.4g = 897.6g = 0.8976kg
molality=moles solute / kg solvent = 2.45moles / 0.8976kg =2.73m.

option B