The freezing point depression of a glucose solution is measured to be 1.71 °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

ΔT = K_fmi

Rearranging to solve for molality, m, we have m = ΔT/(K_f i)

Since this is a nonelectrolyte, i = 1, so the m = (1.71 ^oC/m) / (1.86 ^oC) = 0.919 molal