# to dr bob..chemistry

posted by Lawrence

bottle of wine contains 13.1% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality.
mass percent
_______%
molality
______mol/kg

Thanks

Responses

AP CHEMMMM - DrBob222, Saturday, November 29, 2008 at 11:30pm
I suppose you are to assume the density of the ine to be 1.00. I looked up the density of wine on the Internet and found that it varies between about 0.990 to 1.01 so 100 mL would have a mass of 99 to 101 which isn't that far from 100.
So 13.1% v/v means 13.1 mL ethanol/100 mL solution.
13.1 mL x 0.789 g/mL = 10.34 grams. Check me on that.
Then the solution, with a density of 1.00 will have a mass of 100 grams. So (10.34 g/100 g soln )*100 = 10.34 mass percent.
Molality = mols/kg solvent.
# mols ethanol in 10.34 g = 10.34/46 = 0.225 mol.
We had the ethanol in 100 g and 10.35 of that was ethanol; therefore, the mass of the solvent was 100 - 10.3 = 89.7 g or 0.0897 kg.
molality = 0.225/0.0897 = ??

Check my calculations. Check my thinking. You may need to do the molar mass ethanol again since I estimated it at 46.

your percent mass part was wrong. which threw off the second calc....i thought you did it worng. i cannot find the mistake...

1. Lawrence

i thought you did it right**** sorry

## Similar Questions

1. ### Chem

A bottle of win contains 12.5% ethanol by volume. The density of ethanol (C2H5OH) is .79 g/mL. Calculate the concentration of ethanol in wine as mass percent and molality. I calculated molality as 2.4 m/kg, but I'm stumped on the mass …
2. ### CHEMISTRY MOLALITY!!!!!

A bottle of wine contains 13.1% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality. i don't know how to get molality. please help!!!! …
3. ### chemistry

Please help =) 59. Ethanol, C2H5OH, is responsible for the effects of intoxication felt after drinking alcoholic beverages. When ethanol burns in oxygen, carbon dioxide and water produced. (a) Write a balanced equation for the reaction. …
4. ### AP CHEMMMM

A bottle of wine contains 13.1% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality. mass percent _______% molality ______mol/kg Thanks
5. ### AP Chemistry

A bottle of wine contains 12.5% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality.
6. ### Chemistry

A bottle of wine contains 11.4% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality.
7. ### Chemistry

In the "Methode Champenoise," grape juice is fermented in a wine bottle to produce sparkling wine. The reaction is given below. C6H12O6(aq) 2 C2H5OH(aq) + 2 CO2(g) Fermentation of 712 mL grape juice (density = 1.0 g/cm3) is allowed …
8. ### Chemistry: Dr. Bob, can you check my work?

In the "Methode Champenoise," grape juice is fermented in a wine bottle to produce sparkling wine. The reaction is given below. C6H12O6(aq) 2 C2H5OH(aq) + 2 CO2(g) Fermentation of 712 mL grape juice (density = 1.0 g/cm3) is allowed …
9. ### chemistry

In the "Methode Champenoise," grape juice is fermented in a wine bottle to produce sparkling wine. The reaction is given below. C6H12O6(aq)--> 2 C2H5OH(aq) + 2 CO2(g) Fermentation of 746 mL grape juice (density = 1.0 g/cm3) is allowed …
10. ### Chemistry

Alcoholic drinks contain ethanol. 10cm3 of ethanol is called one unit of alcohol. Men are advised to drink a maximum of 21 units of ethanol a week, while women are advised to drink a maximum of 14 units. Wine contains about 14% ethanol …

More Similar Questions