How do breathalyzers work?

Breathalyzers are used to detect one's alocohol level. This is a very important process that officers use to keep drunk drivers off the road, to ensure the safety of roads. Breathalyzers are a very practical example of how we use physical reactions in our everyday lives. Breathalyzers contain sulfuric acid and other chemicals which react with alcohol. To test a driver's alcohol level, they are required to breathe into the sulfuric acid mixture. The sulfuric acid will then remove the alcohol from the air into a liquid solution. The breathalyzer will change colour, depending on the BAC (blood alcohol content, the ratio of alcohol to blood).