Chemically, How do pH indicators work??

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Chemically, How do pH indicators work??

Could you please explain to me HOW a pH indicator works? WHY do they change colours? If you can give me a chemical equation, that would be nice. Also, if possible, could anyone specifically tell me how the anthocyanin delphinidin (OHOHH- OHOHOH) works??

2007-04-03 12:21:59 · 2 answers · asked by Allieway 3 in Science & Mathematics ➔ Chemistry

Oh, an if possible please give me references! Thanks so much!

2007-04-03 12:24:06 · update #1

2 answers

http://en.wikipedia.org/wiki/Acid-base_indicators

http://chemistry.about.com/library/weekly/aa112201a.htm

2007-04-03 12:28:30 · answer #1 · answered by Dave_Stark 7 · 0⤊ 2⤋

A pH indicator is actually a weak acid. An example would be HIn. When HIn loses a proton, it becomes In-, which exhibits a different color from HIn.

2007-04-03 19:27:36 · answer #2 · answered by coconutty beanz xD 4 · 1⤊ 2⤋