Answer : The mass percent of ethanol is, 10.38 % and the molality of ethanol is, 2.52 mole/kg
Explanation :
In wine, the solute and solvent are ethanol and water respectively.
Given :
12.8 % ethanol by volume means 12.8 mL ethanol present in 100 mL solution.
Volume of ethanol = 12.8 mL
Volume of solution = 100 mL
Volume of water = 100 - 12.8 = 87.2 mL
Density of ethanol =
Density of water = 1 g/mL
Now we have to calculate the mass of ethanol and water.
and,
Now we have to calculate the total mass of 100 mL of wine.
Total mass of 100 mL of wine = 10.1 + 87.2 = 97.3 g
Now we have to calculate the mass percent of ethanol.
The mass percent of ethanol is, 10.38 %
Now we have to calculate the molality.
Molar mass of ethanol = 46 g/mole
The molality of ethanol is, 2.52 mole/kg