If 395.3 g of a substance is dissolved in 872.6 g of cyclohexane solvent, the boiling point of the solution is 87.38 oC. Calculate the apparent molar mass (g/mol) of substance.

Answer 1

Find delta T. That is the difference between the normal boiling point of cyclohexane and 87.38.
delta T = i*Kb*molality
You have delta T, look up Kb (the constant for cyclohexane), and calculate molality.
Then molality = moles/kg
You know molality and kg. Calculate moles.
Finally, moles = grams/molar mass. You know moles and grams, calculate molar mass. This will be the apparent molar mass since you don't know anything about i