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 concentration and boiling point.

Answer 1

The Boiling point of the benzene would be

bp= 80.1C
 kb=2.53

The boiling point of the carbon tetrachrloride would be
bp=80.1
 kb=50.3 

Answer 2

Answer:

The concentration should be 1.32 M and the boiling point 83.44 °C

Explanation:

We have two solutions with the same concentration and the same boiling point.

The first solution is benzene as the solvent and the other has carbon tetrachloride as the solvent.

Useful data on the problem:

Boiling point Benzene pure is 80.1 °C and Kbb = 2.53

Boling point carbon tetrachloride pure 76.8 °C and Kbc = 5.03.

The boiling point of the first solution should be:

B1 = 80.1 + 2.53*X1. Where X1 is the concentration in M (mol/L)

The boiling point of the second solution is:

B2 = 76.8 + 5.03*X2. Where X2 is the concentration in M (mol/L).

Both solutions have the same concentration and the same boiling point. We can use the equalities X1 = X2 = X. B1 = B2

B1 = B2

80.1 + 2.53*X = 76.8 + 5.03*X

We can isolate X.

80.1 - 76.8 = (5.03 - 2.53)X

3.3 = 2.5 X

2.5 X = 3.3

X = 3.3/2.5

X = 1.32 M

The concentration of both solutions X1 = X2 = 1.23 M and the boiling point is

80.1 + 2.53(1.32) = 83.44 °C.

Finally, we can conclude that the concentration should be 1.32 M and the boiling point 83.44 °C.