What are the boiling point and freezing point of a 2.47 m solution of naphthalene in benzene? (The boiling point and freezing point of benzene are 80.1°C and 5.5°C, respectively.)

The boiling point of a 2.47 m solution of naphthalene is 86.25°C.

The freezing point of a 2.47 m solution of naphthalene is -8.53°C.

Explanation:

Elevation in boiling point:

where,

=elevation in boiling point =  

= Boiling point constant  of solvent

= boiling point of solution and pure solvent

m = molality

we have :

=2.53°C/m ,  

m = 2.47m

Boiling point of pure benzene= T =  80.1°C

Boiling point of solution =

The boiling point of a 2.47 m solution of naphthalene is 86.25°C.

Depression in freezing point:

where,

=depression in freezing point =  

= freezing point constant  of solvent

= freezing point of solution and pure solvent

m = molality

we have :

=5.12°C/m ,  2.53

m = 2.47m

Freezing point of pure benzene= T =  5.5°C

Freezing point of solution =

The freezing point of a 2.47 m solution of naphthalene is -8.53°C.