Mixell
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pH dependent color of chemical compound.
Anyone knows a chemical compound (preferably soluble in water) that change color according to the pH (preferably something that is not in the list of
usual pH indicators)?
Thank you in advance.
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m1tanker78
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Without knowing the usual list, red cabbage extract works good for most purposes although it's rather easily bleached.
Tank
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unionised
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What do you think of as "list of usual pH indicators"?
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bbartlog
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What are you trying to do? If you want something that will change color(s) continuously from pH 0 up through pH 14, then you need some sort of mix of
indicators (presumably commercial, synthesizing all of them yourself would be a tall order). If you want something that will give you an indication of
when a particular pH is passed, then it would really help to know what that point is. There are actually quite a number of common organic substances
that provide a red/blue color change at some pH not too far from neutral - red cabbage extract as m1tanker mentions is one example; I have posted in
the biochemistry section, here, about a mulberry pH indicator; there are others, indeed any red/purple berry juice is more likely than not to undergo
some such color change...
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Mixell
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Usual pH indicators:
http://en.wikipedia.org/wiki/PH_indicator#Application
I need it for a school project, it would suite even if the reaction is not reversible or the compound is impractical as an indicator.
On a similar note, I know that there are various metal ions that their species in solutions (type of ligand) depends on the pH, although I don't know
how to check what species I got without checking the pH and appropriate data sources.
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