The boiling point, among the following equimolal aqueous solutions, will be lowest for

Options

A. `La(NO_(3))_(3)`
B. `Ca(NO_(3))_`
C. `C_(6)H_(12)O_(6)`
D. `C_(6)H_(5)NH_(3)Cl`

Answer

3

Explanation

`DeltaT_(b)=iK_(b)m`
For equimolal aqueous, boiling point will be lowest if `DeltaT_(b)` is minimum. This is possible provided van't hoff factor
(i) has least value:
`C_(6)H_(12)O_(6): i=1`
`La(NO_(3))_(3) rarr La^(3+)+3NO_(3)^(-)`
`i=4`
`Ca(NO_(3))_(2) rarr Ca^(2+)+2NO_(3)^(-)`
`i=3`
`C_(6)H_(5) NH_(3)Cl rarr C_(6)H_(5) overset(+)(NH_(3))+Cl^(-)`
`i=2`