Cocaine is a non-electrolyte that has a molecular weight of 303.4 g/mole. How many grams must be dissolved in 25.0 mL of Chloroform (density = 1.484 g/mL) to raise its boiling point to 65.5 Celsius? The boiling point of pure Chloroform is 61.2 Celsius.

Question

Cocaine is a non-electrolyte that has a molecular weight of 303.4 g/mole. How many grams must be dissolved in 25.0 mL of Chloroform (density = 1.484 g/mL) to raise its boiling point to 65.5 Celsius? The boiling point of pure Chloroform is 61.2 Celsius.
Kb Chloroform = 3.62 Celsius/m

Again I know to solve for m. But then I don't know how to find the boiling point of pure Chloroform or what steps to even take next/what numbers to plug in.

DrBob222 · Answer

Why do you have a problem with the boiling point of pure CHCl3? The problem gives that to you as 61.2 C.

Determine delta T, then
delta T = Kb*m
Solve for m

m cocaine= moles cocaine/kg solvent
You now know m cocaine, you know kg solvent, solve for moles cocaine.

moles cocaine = grams cocaine/molar mass cocaine.
Solve for grams.