Answer:
Molality of both benzene and carbon tetrachloride is 1.32 m .
boiling point is 83.4396 °C
Step-by-step explanation:
When a non-volaile solute is added to a solvent, its boiling point increases. The relationship increase in temperature and molality of the solute is given as follows:
ΔT = m × Kb
Boiling point of pure benzene is 80.1 °C.
Molal elevation boiling constant of benzene (k_b) is 2.53 °C/m
Increase in boiling point of benzene = m × 2.53
Therefore, Boiling point of benzene solution = 80.1 + 2.53m
Boiling point of pure carbon tetrachloride is 76.8 °C
Molal elevation boiling constant of carbon tetrachloride (k_b) is 5.03 °C/m
Increase in boiling point of benzene = m × 5.03
Therefore, Boiling point of carbon tetrachloride solution = 76.8 + 5.03m
It is given that boiling point of both the solutions are same therefore,
76.8 + 5.03m = 80.1 + 2.53m
5.03m - 2.53m = 80.1 - 76.8
2.5m = 3.3
m = 1.32
Molality of both benzene and carbon tetrachloride is 1.32 m
Boiling point of the solutions = 80.1 + 2.53 × 1.32
= 83.4396 °C