We’re being asked to** ****calculate the mass of**** ethanol** in a **12-oz** serving of* light beer* which contains **4.4 % ethanol by volume** given its *density*.

Recall that we can solve for the **volume percent **using the equation:

$\overline{){\mathbf{volume}}{\mathbf{}}{\mathbf{percent}}{\mathbf{=}}\frac{\mathbf{volume}\mathbf{}\mathbf{component}}{\mathbf{total}\mathbf{}\mathbf{volume}}{\mathbf{\times}}{\mathbf{100}}}$

This means, that the **% by volume ethanol in light beer ***(solution) *is given by the equation:

$\overline{){\mathbf{\%}}{\mathbf{}}{\mathbf{volume}}{\mathbf{=}}\frac{\mathbf{volume}\mathbf{}\mathbf{ethanol}}{\mathbf{volume}\mathbf{}\mathbf{solution}}{\mathbf{\times}}{\mathbf{100}}}$

We can determine the **mass of ethanol** by using its density after** finding its volume** in light beer.

**volume ethanol (density) → mass ethanol**

One of the best-selling light, or low-calorie, beers is 4.4 % 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. * *

*If 4.4
% 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?*

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 Mass Percent concept. You can view video lessons to learn Mass Percent. Or if you need more Mass Percent practice, you can also practice Mass Percent practice problems.

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