Question

By weight, 23% NaCl and 19.5% MgCl2 are present in salt water. The degree of dissociation of both salts is 100%. Find the average boiling point of salt water (inºC). (Kb = 0.52 K kg mol–1) (Nearest integer)

Answer 1

The correct answer is : 113
$\Delta T_b=iK_bm$
$=(\frac{23 \times 2 \times1000}{(58.5) \times 57.5}+\frac{3\times19.5\times1000}{95\times57.5})\times 0.52$
$=\frac{(7.86+6.16)\times0.52}{57.5}\times100 \simeq12.66$
$\therefore$ Boiling point $\simeq$ 113$^{\circ}$C