Problem: The boiling point of ethanol (C2H5OH) is 78.5°C. What is the boiling point of a solution of 6.4 g of vanillin (ℳ = 152.14 g/mol) in 50.0 g of ethanol (Kb of ethanol = 1.22°C/m)?

🤓 Based on our data, we think this question is relevant for Professor Beck's class at OHIO.

FREE Expert Solution
FREE Expert Solution

We’re being asked to determine the boiling point of a solution. The solution is composed of 6.4 g vanillin in 50.0 g ethanol


Recall that the boiling point of a solution is higher than that of the pure solvent and the change in boiling point (ΔT­b) is given by:



The change in boiling point is also related to the molality of the solution:



where: 

i = van’t Hoff factor

m = molality of the solution (in m or mol/kg)

Kb = boiling point elevation constant (in ˚C/m)


Recall that the molality of a solution is given by:



View Complete Written Solution
Problem Details

The boiling point of ethanol (C2H5OH) is 78.5°C. What is the boiling point of a solution of 6.4 g of vanillin (ℳ = 152.14 g/mol) in 50.0 g of ethanol (Kb of ethanol = 1.22°C/m)?