# Which of the given solutions should display the GREATEST departure from the freezing point, and the boiling point of the water solvent?

## $A .$ $L i C l \left(a q\right)$ $B .$ $N a C l \left(a q\right)$ $C .$ $\text{sucrose} \left(a q\right)$ $D .$ $N {a}_{3} P {O}_{4} \left(a q\right)$ $E .$ $M g B {r}_{2} \left(a q\right)$

Jan 30, 2017

Probably $D$ if EQUAL, formal concentrations of each salt were prepared.

#### Explanation:

The more particles in solution, the greater the $\text{freezing point depression}$, and the greater the $\text{boiling point elevation}$

All these solutes speciate in aqueous solution to give a number of different particles:

$A .$ $L i C l \left(s\right) \rightarrow L {i}^{+} + C {l}^{-}$

$B .$ $N a C l \left(s\right) \rightarrow N {a}^{+} + C {l}^{-}$

$C .$ $\text{sucrose"(s)rarr "sucrose} \left(a q\right)$

$D .$ $N {a}_{3} P {O}_{4} \left(s\right) + {H}_{2} O \rightarrow 3 N {a}^{+} + H P {O}_{4}^{-} + H {O}^{-}$

$E .$ $M g B {r}_{2} \left(s\right) \rightarrow M {g}^{2 +} + 2 B {r}^{-}$

Clearly the phosphate ion delivers the most species, the most ions, in aqueous solution. And thus this species should give the greatest $\text{boiling point elevation}$.