# Problem: One of the best-selling light, or low-calorie, beers is 4.2 % alcohol by volume and a 12-oz serving contains 110 Calories; remember: 1 Calorie = 1000 cal = 1 kcal. To estimate the percentage of Calories that comes from the alcohol, consider the following questions.(a) Write a balanced chemical equation for the reaction of ethanol, C2H5OH, with oxygen to make carbon dioxide and water. (b) Use enthalpies of formation in Appendix C to determine ΔH for this reaction. (c) If 4.2% of the total volume is ethanol and the density of ethanol is 0.789 g/mL, what mass of ethanol does a 12-oz serving of light beer contain? (d) How many Calories are released by the metabolism of ethanol, the reaction frompart (a)?

###### FREE Expert Solution

ΔH˚rxn:

Combustion produces CO2 and H2O

• Complete reaction: C2H5OH + O→ CO2 + H2O
• add coefficients to balance (same number of atoms for both sides)
96% (48 ratings) ###### Problem Details

One of the best-selling light, or low-calorie, beers is 4.2 % alcohol by volume and a 12-oz serving contains 110 Calories; remember: 1 Calorie = 1000 cal = 1 kcal. To estimate the percentage of Calories that comes from the alcohol, consider the following questions.

(a) Write a balanced chemical equation for the reaction of ethanol, C2H5OH, with oxygen to make carbon dioxide and water.

(b) Use enthalpies of formation in Appendix C to determine ΔH for this reaction.

(c) If 4.2% of the total volume is ethanol and the density of ethanol is 0.789 g/mL, what mass of ethanol does a 12-oz serving of light beer contain?

(d) How many Calories are released by the metabolism of ethanol, the reaction from
part (a)?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Enthalpy of Formation concept. You can view video lessons to learn Enthalpy of Formation. Or if you need more Enthalpy of Formation practice, you can also practice Enthalpy of Formation practice problems.