What Is a Confirmatory Test in Chemistry?

A confirmatory test is a controlled chemical reaction used to determine the presence of a specific ion or compound in a solution or substance. Confirmatory tests are commonly used after an experiment in a laboratory setting to determine if the reaction proceeded to completion or if the desired products were produced.

While there are several different kinds of confirmatory tests, one of the most common ones is a pH indicator test. Special chemical solutions called indicators are used to determine the pH of a solution. Indicators change colors when in the presence of certain pH ranges. Natural pH indicators can be made out of certain fruits and vegetables that contain anthocyanins, but litmus paper and laboratory-grade indicator solutions are also commercially available.

Confirmatory testing is a powerful tool in qualitative chemistry and has several practical applications. Forensic testing, for example, is based on using confirmatory tests to determine chemical compounds found in blood, tissue and crime scene samples. Anything from certain drugs to DNA can be found using confirmatory testing. Because confirmatory testing is specific, in that each individual test can only test for a specific compound or group of compounds, multiple procedures are required to discover all of the relevant information required to solve a crime.