Breathalyzer test

The following redox reaction is used in acidic solution in the Breathalyzer test to determine the level of alcohol in the blood ... 

The reaction of alcohol with orange dichromate ions to produce blue-green chromium(III) ions is used in the Breathalyzer test, a test that measures the presence of alcohol in a person s breath. How could a colorimeter be used in this analysis ... 

The police may pull over a driver weaving erratically on the highway on suspicion of drunk driving. A police officer must confirm this suspicion by assessing whether the driver has a blood alcohol concentration over the "legal limit." The "Breathalyzer" test checks a person s breath using a redox reaction to determine blood alcohol concentration. This test was invented in 1953 by Robert Borkenstein, a former member of the Indiana State Police, and a professor of forensic studies. 

In the Breathalyzer test, the subject blows into a tube connected to a vial. The exhaled air collects in the vial, which already contains a mixture of sulfuric acid, potassium dichromate, water, and the catalyst silver nitrate. The alcohol reacts with the dichromate ion in the following redox reaction. 

One type of breathalyzer detects whether ethanol is in the breath of a person. Ethanol is oxidized to acetaldehyde by dichromate ions in acidic solution. The dichromate ion in solution is orange, while the Cr + aqueous ion is green. The appearance of a green color in the breathalyzer test shows that the breath exceeds the legal limit of alcohol. The equation is... 

As already stated, the source of biological material is also important either due to its accessibility (i.e., noninvasive nature) or due to the fact that the analytes to be measured are restricted to certain locations. Biomarkers can be detected in all biological entities (i.e., fluids, gases, and tissues), and depending on what is to be measured each biological source has a specific niche. For example the fact that alcohol is excreted in the lung, combined with the convenience of using exhaled air, has been exploited for many years in the breathalyzer test as an indirect measurement of blood alcohol levels [5 ]. Stool is commonly used for the detection of parasites and infections. Tears have been proposed to detect and treat ocular toxicity [6], Urine has also been used extensively to measure both renal and non-renal injuries. However, for the most part, blood (serum or plasma) and urine are the most utilized sources. 

Organic alcohols react with orange dichromate ions, producing blue-green chromium(lll) ions. This reaction is used in a Breathalyzer test to test for the presence of alcohol in a person s breath. In this MiniLab, you win use this reaction to test for the presence of alcohol in a number of household hygiene, cosmetic, and cleaning products. 

During a Breathalyzer test, a person blows into the mouthpiece of the bag. 

Suppose a person used mouthwash shortly before taking a Breathalyzer test. What might be the result ... 

How would the color produced in a Breathalyzer test change as the ethanol content of the blood increases ... 

If ethanol were less volatile, how might the usefulness of a Breathalyzer test be affected Explain. 

The Human Perspective Alcohol Consumption and the Breathalyzer Test (Chapter 13), describes the reaction between the dichromate ion and ethanol to produce acetic acid. How much acetic acid can be produced from a mixture containing excess of dichromate ion and 1.00 X 10 g of ethanol ... 

The loss of some coordination and reflex action is particularly serious when the affected individual attempts to operate a motor vehicle. Law enforcement has come to rely on the "breathalyzer" test to screen for individuals suspected of driving while intoxicated. Those with a positive breathalyzer test... 

The breathalyzer test is a technological development based on a scientific understanding of the chemical reactions that ethanol may undergo—a further example of the dependence of technology on science. 

If the person fails this test—determined by the extent to which the green color spreads through the tube—a more accurate Breathalyzer test is administered. The Breathalyzer test also depends on the oxidation of breath ethanol by sodium dichromate, but it provides more accurate results because it is quantitative. In the test, a known volume of breath is bubbled through an acidic solution of sodium dichromate, and the concentration of chromic ion is measured precisely with a spectrophotometer. 

A chemical "breathalyzer" test works because ethanol in the breath is oxidized by the dichromate ion (orange) to form acetic acid and chromium(lll) ion (green). The balanced reaction is... 

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