Chemistry - Liquid Solution Question with Solution | TestHub

Boiling point elevation is a colligative property, which depends on the total number of solute particles in the solution.

$\Delta T_b=i\times K_b\times m$

For complete dissociation, the van't Hoff factor $i$ is equal to the number of ions produced per formula unit.

For $0.2\text{ m KCl}$: $i=2$, $i\times m=2\times 0.2=0.4$

For $0.1\text{ m NaCl}$: $i=2$, $i\times m=2\times 0.1=0.2$

For $1{\text{ m AlCl}}_3$: $i=4$, $i\times m=4\times 1=4$

For $0.05{\text{ m MgCl}}_2$: $i=3$, $i\times m=3\times 0.05=0.15$

Since $0.05{\text{ m MgCl}}_2$ has the minimum value of $i\times m$, it exhibits the minimum boiling point elevation.

Answer: $0.05\mathrm{m}{\mathrm{MgCl}}_2$