Which of the following solutions have lowest freezing point ?

Options

A. 0.1 M glucose
B. 0.1 M NaCl
C. 0.1 M `BaCl_(2)`
D. 0.1 M urea

Answer

C

Explanation

`Delta T_(b)` will depend upon the number of particles given by the solute in the solution (concentration is same).
(A) 0.1 M glucose (0.1 mole particles)
(B) 0.1 M NaCl (`NaCl hArr Na^(+)+Cl^(-),0.2` mole particles)
(C) `0.1 M BaCl_(2)(BaCl_(2) hArr Ba^(2+)+2Cl^(-), 0.3 "mole particles")`
(D) 0.1 M urea (0.1 mole particles).
`DeltaT_(b)` will be largest for C and , therefore, boiling point will be largest.