Question

Imagine two solutions with the same concentration and the same boiling point, but one has benzene as the solvent and the other has carbon tetrachloride as the solvent. Determine that molal concentration, m (or b), and boiling point, Tb.
benzene boiling point=80.1 Kb=2.53

carbon tetrachloride boiling point=76.8 Kb=5.03

Answer 1

Answer:

Concentration = 1.32 m

Boiling point = $83.44^{0}C$

Explanation:

Let the boiling point of two solutions = T

Let the molal concentration of the two solutions= m

The relation between elevation in boiling point and molal concentration is:

$elevationinboiling point=K_{b}Xmolality$

i) For benzene

$T-80.1=2.53Xm$

$T=2.53m+80.1$ ....(1)

ii) For carbon tetrachloride

$T-76.8=5.03Xm$

$T=5.03Xm+76.8$ ...(2)

Equating the two equations:

$5.03Xm+76.8=2.53m+80.1\\m=1.32molal$

Putting value of "m" in equation "1"

$T=2.53(1.32)+80.1=83.44^{0}C$