Which of the following is the ratio of the lowering of vapour pressure of 0.1 M aqueous solutions of `BaCI_(2)` NaCl and `AI_(2) (SO_(4))_(3)` respectively.

Options

A. `3:2:5`
B. `5:2:3`
C. `5:3:4`
D. `2:3:5`

Answer

(a)

Explanation

`BaCl_(2)= Ba_(2+) + 2Cl_(-)= 3 ions`
  `NaCI = Na^(+) + Cl^( -)= 2 ions`
`Al_(2)(SO_(4))_(3)= 2Al^(3+)+3S0_(4)^(2-) = 5 ions`
Since lowering of vapour pressure is a colligative property and it depends on the number of particles of the solute, the ratio of lowering of vapour pressure of `Bacl_(2)`, NaCl and `Al_(2)(SO_(4))_(3)` is 3 : 2:5.