Friday
May 6, 2016

# Homework Help: chem

Posted by alicia on Wednesday, February 13, 2008 at 4:33pm.

drbob you helped me with this problem the other day but i have a question.
-i changed 500mL of ethanol to grams then to mol. i was wondering if i then used 1000mL or 500mL of water to change to kg?

The "proof" of an alcoholic beverage is twice the volume percent of ethanol, C2H5OH, in water. The density of ethanol is 0.789g/mL and that of water is 1.00g/mL. A bottle of 100-proof rum is left outside on a cold winter day. a) Will the rum freeze if the temperature drops to -18 degrees C?
b) Rum is used in cooking nd baking. At what temperature does 100-proof rum boil?
• chem - DrBob222, Wednesday, February 13, 2008 at 5:34pm

I can't remember the details of the problem and my answer. I think the alcoholic beverage was 100 proof which means 50% v/v (volume/volume). That means we have 500 mL ethanol + 500 mL water (assuming water and alcohol volumes are additive and they are not), so you convert 500 mL ethanol to grams and that to mols. Then you convert 500 mL H2O to grams and that to kg. Then you can use delta T = kf*m. Does that answer your question. I'm sorry to have taken so long but I didn't remember what we did so I answered some other questions while I whirled this one around in my head. I hope I didn't give bad advice on both. :0)

• chem - alicia, Wednesday, February 13, 2008 at 5:39pm