Final answer:
A 5-ounce glass of 12% wine contains approximately 0.304 moles of ethanol, which is calculated by first determining the volume of ethanol, then its mass, and finally using molar mass to find the number of moles.
Step-by-step explanation:
The student is inquiring about the amount of ethanol in a 5-ounce glass of wine with a 12% alcohol concentration by volume. To answer this, we need to calculate the volume of ethanol and then determine the number of moles contained in that volume. First, calculate the ethanol volume in a 5-ounce glass by using the given percentage concentration:
5 ounces (approx. 148 mL) x 12% (0.12) = 17.76 mL of ethanol
Then, determine the mass of ethanol using the density provided:
17.76 mL x 0.789 g/mL (density of ethanol) = 14.01 grams of ethanol
Lastly, calculate the number of moles of ethanol using its molar mass:
14.01 g ÷ 46.06 g/mol (molar mass of ethanol) = 0.304 moles of ethanol
Therefore, a 5-ounce glass of 12% wine contains approximately 0.304 moles of ethanol.