A breathalyzer measures a color change after a chemical reaction and uses it to calculate the person's blood alcohol concentration (BAC). Since alcohol is not digested, it is absorbed directly into the bloodstream from the mouth, throat and stomach. As the blood circulates around the lung's air sacs, the alcohol evaporates into the air. Each breath, then, contains an alcohol concentration that is proportional to that of the blood.Know More
When the test subject blows into the breathalyzer, the air sample bubbles into a vial containing a mixture of chemicals. As the alcohol reacts, the solution turns from red-orange to green. Because the presence of the green color correlates to the amount of alcohol that was present, the breathalyzer measures the extent of the color change and uses the result to determine the BAC.
Though many techniques have been developed to trick the breathalyzer, most, like chewing gum or pennies, do not work. Others, on the other hand, actually make the test results worse. For instance, using a mouthwash or breath spray that contains alcohol, or even breath mints that contain sugar alcohol, can increase measured BAC. Additionally, holding a breath before the test allows more alcohol to diffuse into the lungs, increasing its concentration.Learn more about Conditions & Diseases
A chemical gradient is a concentration gradient that shows a slow or gradual change in molecular density. It is a concept in mathematics that is used to measure the change of a scalar function over a set distance.Full Answer >
A burning candle is an example of a chemical change because the paraffin wax, which is a hydrocarbon, undergoes a chemical reaction with oxygen to form water and carbon dioxide gas. Because the chemical structure of the paraffin has been altered, this is a chemical change.Full Answer >
There are a few telltale signs that can help indicate that a chemical reaction has taken place; these include the creation of one or more new substances and a noticeable energy change from the reaction site. However, telling whether a chemical reaction has actually taken place is not always very easy to observe.Full Answer >
A substance that undergoes a change in a chemical reaction is called a reactant or reagent. Usually, chemical reactions comprise of the changes that only pertain to the movement of electrons in the forming and breaking of chemical bonds.Full Answer >