Pure Chloroform, CHCl₃, Has a Boiling Point of 61

Multiple Choice

Pure chloroform, CHCl₃, has a boiling point of 61.23°C. Its boiling point elevation constant, K_b, is 3.63°C m^-1. A solution was made by taking 11.25 g of an unknown nonelectrolyte and dissolving it in 115.5 g of chloroform. The measured boiling point of the solution was 65.46°C. Calculate the molecular weight of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

A) 83.6 g mol^-1
B) 113 g mol^-1
C) 114 g mol^-1
D) 120 g mol^-1
E) 158 g mol^-1