# chemistry

posted by .

a student determines the molar mass of methanol by the method used in this experiment. she found that the equilibrium temperature of a mixture of ice and pure water was .4 degrees Celsius on her thermometer. when she added 10g of her sample to the mixture, the temperature, after thorough stirring, fell to -5.4 degrees Celsius. she poured off the solution through a screen into a beaker. the mass of the solution was 101.8 g.

what was the freezing point depression?

what was the molality of the methanol?

how much methanol was in the decanted solution?

how much water was in the decanted solution?

how much methanol would there be in the solution with 1 kg of water, with methanol at the same concentration as she had in her experiment?

what did she find to be molar mass of methanol, assuming she made the calculation properly?

• chemistry -

I don't want to do all of this but I can get you started. You can post back here if there is something you don't understand.

what was the freezing point depression?
Wouldn't that be the difference between -5.4 and 0.4 or 5.8 degrees C?

what was the molality of the methanol?
delta T = Kf*m
You know delta T and Kf, solve for m

how much methanol was in the decanted solution?
Doesn't the problem tell you that she added 10g to the ice bath?

how much water was in the decanted solution?
Hmm...The mass of the decanted material was 101.8g and the methanol was 10 g so.....

how much methanol would there be in the solution with 1 kg of water, with methanol at the same concentration as she had in her experiment?

what did she find to be molar mass of methanol, assuming she made the calculation properly?