How many grams of ethanol must be added to 500.0 g of water to make a solution that freezes at 0.00 degrees fahrenheit? The molal freezing point depression constant for water is 1.86 degree celsius over moles.

Answer 1

C=5/9(F-32)=-160.9=-17.7 C

-17.7C=-1.86 (molesethantol/.5kg)

solve for moles ethanol, convert to grams.

I get about 4.75moles, or about 220 grams.