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A '''universal indicator''' is a [[pH indicator]] made of a solution of several compounds that exhibits several smooth color changes over a wide range pH values to indicate the acidity or alkalinity of solutions.

Although there are several commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1933. Details of this patent can be found in Chemical Abstracts. Experiments with Yamada's universal indicator are also described in the Journal of Chemical Education.

A universal indicator is typically composed of [[water]], [[ethanol]]/[[propanol]], [[phenolphthalein]] sodium salt, [[sodium hydroxide]], [[methyl red]], [[bromothymol blue]] monosodium salt and [[thymol blue]] monosodium salt.

==See also==
*[[pH test strip]]

==References==
<references/>
===Relevant Sciencemadness threads===
*[http://www.sciencemadness.org/talk/viewthread.php?tid=14894 How to prepare universal indicator - a recipie]

[[Category:PH indicators]]