Final answer:
The concentration of ethanol in the solution can be calculated using the mass percentage formula. Therefore, the concentration of ethanol in the solution is (39.5 g / 439.5 g) * 100 = 8.99%.
Step-by-step explanation:
The concentration of ethanol in the solution can be calculated using the mass percentage formula.
The mass of ethanol can be found by multiplying the volume of ethanol by its density.
The mass of the solution is the sum of the mass of ethanol and the mass of water.
Dividing the mass of ethanol by the mass of the solution and multiplying by 100 gives the mass percentage of ethanol in the solution.
For example, if we have 50 mL of ethanol and 400 mL of water, the mass of ethanol would be 50 mL * 0.79 g/mL = 39.5 g.
The mass of water would be 400 mL * 1 g/mL = 400 g.
The mass of the solution is 39.5 g + 400 g = 439.5 g.
Therefore, the concentration of ethanol in the solution is (39.5 g / 439.5 g) * 100 = 8.99%.