Question

The BAC is usually expressed as a percent based on weight/volume. This means that the BAC is the grams (g) of alcohol present per 100 mL of blood. For example, a BAC of 0.12% is equivalent to 0.12 g alcohol per 100 mL of blood. At 0.12%, most people are intoxicated! Typically 100 mL is referred to as 1 deciliter or 1 dL. So, 0.12% is also equivalent to 0.12 g/dL. The BAC can be calculated based on how much alcohol one drinks and the volume of water in the body. Alcohol dissolves into water and is in equilibrium between the water and the bloodstream. This means alcohol constantly switches between water and the bloodstream. We can simply calculate the alcohol in the blood. It takes a few mathematical steps to do this calculation Exercise Calculate the BAC of a 160 lb man who drank 4 beers and indicate whether you think he is drunk. A typical can of beer contains 12 fluid ounces (of fluid, not alcohol!). To calculate the BAC, you must know: 1. the amount of alcohol ingested an estimate of the individual's water volume

Answer 1

1).No. of Beer consumed = 4

1beer = 12 fluid ounces

Total beer consumed = 4 × 12 fluid ounces = 48 fluid ounces

As beer has 5 vol% alcohol

Alcohol consumed = 0.05 × 48 fluid ounces = 2.4 fluid ounces

1 fluid ounce = 29.6 mL

Alcohol consumed = 2.4 × 29.6 mL = 71.04 mL

Density of alcohol = 0.79 g/mL

Alcohol consumed = 71.04 × 0.79 g = 56.1216 g

2). Weight of man = 160 lb = 160 lb × 0.453 kg/lb = 72 48 kg

(As 1lb = 0.453 kg)

Volume of man's body = 72.48 kg × 1000 mL/kg = 72480 mL

Volume of water in man's body = 0.68 × 72480 mL = 49286.4 mL

3). BAC = (g of ethanol consumed)/ (volume of water in man's body in mL) = 56.1216 g / 49286.4 mL = 0.0011387 = 0.11387 %

4). As 1 dL = 100 mL

So, 49286.4 mL = 492.864 dL

BAC = 56.1216 g/ 492.864 dL = 0.11387 g/dL

5). The legal definition of intoxication has BAC = 0.08%

As BAC in person = 0.11387%, this means the person is intoxicated as amount found is greater than as per legal definition.

6). Metabolism for ethanol in body takes place in liver. The ethanol is first converted into aldehyde by alcohol dehydrogenase with peroxisomes and microsomes which is then converted into acetate by aldehyde dehydrogenase with mitochondria.