Vapour pressure of a solution of `5g`of non-electrolyte in `100g`water at a particular temperature is`2985N//m^(2)`.The vapour pressure of pure water is`3000N//m^(2)`.The molecular weight of the solute is

Options

A. `60`
B. `120`
C. `180`
D. `380`

Answer

C

Explanation

`(P^(0)-P^(s))/(P^(0))=((W_(2))/(M_(2)))/((W_(1))/(M_(1)))=(3000-2985)/(3000)=((5)/(M_(2)))/((100)/(18)) or M_(2)=180`