Final answer:
It takes an average adult around 2.5 hours to metabolize the ethanol in one beer, with the liver handling the majority of alcohol metabolism. Legal sobriety from a BAC of 0.08 typically requires at least five hours. External factors like coffee have no effect on speeding up this process.
Step-by-step explanation:
On average, it takes an average 70 kg person about 2.5 hours to metabolize the ethanol contained in a single can of beer, which is approximately 15 mL of ethanol. This process occurs in the liver, where up to 98% of ingested alcohol is metabolized. The substance first transforms into acetaldehyde and subsequently into other products through a series of reactions. Women may metabolize alcohol more slowly compared to men, and factors such as body size and liver enzyme levels can cause individual variation. While the metabolic rate remains constant regardless of the alcohol quantity consumed, a legally intoxicated person with a blood alcohol concentration (BAC) of 0.08 will require at least five hours to reach sobriety after drinking stops. It's important to note that measures like drinking coffee do not accelerate the metabolism of alcohol.