Question

What is a particular beer's ethanol content by volume?

a) 3.25%
b) 4.50%
c) 6.50%
d) 8.75%

Answer 1

To find the moles of ethanol in a wine bottle, calculate the volume of ethanol from the volume percentage, convert it to mass using the density, and then find the number of moles with the molar mass. In a 12% ethanol by volume 750-mL wine bottle, about 1.54 moles of ethanol are present.

Step-by-step explanation:

Calculating the Moles of Ethanol in Wine

To calculate the moles of ethanol in wine, we use the given percentage of ethanol by volume, the density of ethanol, and its molar mass. For a 12% ethanol solution in a 750-mL bottle, the calculations would involve the following steps:

1. Calculate the volume of ethanol: 750 mL × 12% = 90 mL.
2. Convert the volume of ethanol to mass using the density: mass = volume × density = 90 mL × 0.789 g/mL = 71.01 g.
3. Finally, calculate the number of moles using the molar mass of ethanol: moles = mass / molar mass = 71.01 g / 46.06 g/mol = approximately 1.54 moles.

Therefore, there would be approximately 1.54 moles of ethanol in a 750-mL bottle of 12% ethanol by volume wine.