Question

What is the boiling point of an benzene solution that freezes at 0.3 degrees C? Normal freezing point is 5.5 and the normal boiling point is 80.1 degrees C. Kfp = 5.12 K/m and Kbp = 2.53 K/m. Enter your answer to 2 decimal places.

Answer 1

Answer: The boiling point of an benzene solution is
`82.57^0C`

Step-by-step explanation:

Depression in freezing point is given by:

`\Delta T_f=i* K_f* m`

`\Delta T_f=T_f^0-T_f=(5.5-0.3)^0C=5.2^0C=5.2K` = Depression in freezing point

i= vant hoff factor = 1 (for non electrolyte)

`K_f` = freezing point constant =
`5.12K/m`

m= molality

`5.2=1* 5.12* m`

`m=1.015`

Elevation in boiling point is given by:

`\Delta T_b=i* K_b* m`

`\Delta T_b=Tb-Tb^0=(Tb-80.1)^0C` = elevation in boiling point

i= vant hoff factor = 1 (for non electrolyte)

`K_b` = boiling point constant =
`2.43K/m`

m= molality = 1.015

`(T_b-80.1)^0C=1* 2.43* 1.015`

`T_b=82.57^0C`

Thus the boiling point of an benzene solution is
`82.57^0C`