The measured osmotic pressure of a soultion prepared by dissolving 17.4 mg of `K_(2)SO_(4)` in 2L of water at `27^(@)C" is "3.735xx10^(-3)` bar. The van't Hoff factor is (`R =0.083 L" bar "K^(-1) mol^(-1)`, atomic weights k=39, S=32, O=16)

Options

A. `2.84`
B. `3.0`
C. `2.0`
D. 2.32`

Answer

B

Explanation

Given, `pi =3.735xx10^(-3)` bar Mass of `K_(2)SO_(4)(omega) =17.4 mg`
Volume =2L
Temperature `(T) =27^(@)C=27+273=300 K`
From osmotic pressure of solution
`pi =iCRT`
I = van.t Hoff factor
`i=pi//CRT`
`=(pixxMxxV)/(omega xx R xx T) =(3.735xx174xx2)/(17.4xx0.083xx300)`
Molar mass `(M) H_(2)SO_(4) =174, i=3.0`