Calculate the boiling point of a water solution at each concentration.

(a) 0.225 m

(b) 2.58 m

(c) 4.33 m

(d) 6.77 m

Solution 104P:

Here, we are going to calculate the boiling point of a solution at each concentration.

The boiling point rises in solutions is calculated by the equation:

Tb= m x Kb

Where m is the molality of the solution and Kb is the boiling point elevation constant for the solvent.

(a) 0.225 m

Kb for water = 0.512 oC/m

From equation(1) we have

Tb= m x Kb = 0.225 m x 0.512 oC/m = 0.1152 oC

The normal boiling point of water is Tbo =100oC

Thus, the boiling point of solution Tb= Tb +Tbo = 100oC + 0.1152 oC = 100.115 oC

Therefore, the boiling point of a solution at 0.225 m is 100.115 oC.

(b) 2.58 m

Kb for water = 0.512 oC/m

From equation(1) we have

Tb= m x Kb = 2.58 m x 0.512 oC/m = 1.3209 oC

The normal boiling point of water is Tbo=100oC

Thus, the boiling point of solution Tb= Tb +Tbo ...