Question

A`5%` solution of cane sugar (molar mass =`342`)is isotonic with `1%`of a solution of an known solute.The molar mass of unknown solute in g/mol is
A. `136.2`
B. `171.2`
C. `68.4`
D. `34.2`

Answer 1

Correct Answer - C
`P_(c.s) = P_(Unk)`
`((n)/(V))_(c.s) RT = ((n)/(V))_(unk) RT`
`(5 xx 10)/(342) = (1xx10)/(M)`
`M = 68.4 gm//mol`