The boiling point elevation of a glucose solution is measured to be 1.34 °C. What is the molal concentration of this solution?

Question

Some possibly useful constants for glucose (C₆H₁₂O₆, 180.16 g/mol) and water are K_f = 1.86°C/m , K_b = 0.512°C/m, freezing point = 0°C, and boiling point = 100°C.

 

Enter your value with 2 decimal values

Answer 1

Use the following equation:

∆T = imK

∆T = change in boiling poit = 1.34º

i = van't Hoff factor = 1 for glucose since it is a non electrolyte

m = molality = ?

K = boiling constant = 0.512º/m

Solving for m we have...

m = ∆T / iK

m = 1.34 / (1)(0.512)

m = 2.62