Tennessee MPJE Practice Exam 2026 – Complete Study Resource

To determine the proof of a liquid, particularly ethanol, you can use the formula that relates proof to the percentage of ethanol. In the United States, proof is defined as twice the percentage of alcohol by volume. Therefore, for ethanol, you can first convert the percentage into proof by applying the general rule:

Proof = 2 × (% Alcohol by Volume).

In this case, the ethanol concentration is 70%. When you apply the formula, you multiply the percentage of ethanol by 2:

Proof = 2 × 70 = 140 proof.

However, the question asks for the proof in terms of gallons. To find the proof gallons, you multiply the proof of the ethanol by the volume of the liquid in gallons. In this case:

Proof gallons = (Proof × Volume in gallons) / 100.

So, plugging in the numbers:

Proof gallons = (140 × 10) / 100 = 14 proof gallons.

Thus, the calculation correctly leads to 14 proof gallons, making this option the most accurate response based on the information provided and the formula utilized. Understanding this concept illuminates the relationship between the concentration of ethanol and its proof, grounding how you measure the alcoholic strength of a solution.