Question

Freezing point of an aqueous solution is `-0.186^(@)C`. Elevation of boiling point of the same solution is ……..if `K_(b)=0.512 K "molality"^(-1)`and `K_(f)=1.86K "molality"^(-1)` :
A. `0.186^(@)C`
B. `0.0512^(@)C`
C. `0.092^(@)C`
D. `0.237^(@)C`

Answer 1

Correct Answer - B
`Delta T_(f) = (1000.K_(f).w)/(W.m)`
and `Delta T_(b) = (1000.K_(b).w)/(W.m)`
`:. (Delta T_(f))/(Delta T_(b)) = (K_(f))/(K_(b)) or (0.186)/(Delta T_(b)) = (1.86)/(0.512)`
`:. Delta T_(b) = 0.0512^(@)C`