If A soulution remains colourless when phenolphthalien is added, does this mean that the soloution is an acid? Explain?
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If A soulution remains colourless when phenolphthalien is added, does this mean that the soloution is an acid? Explain?
Strictly speaking it means that it is not a base and may be acidic.Quote:
Originally Posted by neotheone
omg chemistry noob, i'm not gonna help you.
Oh go on, tell him it's because the molecule is colourless and the ion is pink, therefore the more pink the higher level of ions.Quote:
Originally Posted by rnanker
it's due to the refraction of the chemistry coat and the refractive index of the acid that causes the reflective properties of the dissicioative ions in the acid, which is more than the non-dissacioating ions in the alkalie.
That's the ticketQuote:
Originally Posted by rnanker
no thats an answer
indeedQuote:
Originally Posted by rnanker
no an answer not a deed.
a deed, that's the answerQuote:
Originally Posted by rnanker
Phenolphthalein is an organic compound (C20H14O4) used as an acid-base indicator. The compound is colorless in acidic solution and pinkish in basic solution (with the transition occuring around pH 9).
Phenolphthalein does not dissolve very well in water, so for titrations it is usually prepared in alcohol solution. When adding a drop of indicator to an acid you will sometimes detect a slight cloudy white color. This is actually a precipitate of solid phenolphthalein, as the high local concentration exceeds the solubility product. It will usually dissappear if you shake the solution, since enough solvent becomes available to dissolve the solute.
Phenolpthalein was used for many years as the active ingredient in Ex-Lax. However, recent (and controversial) concerns about its possible carcinogenicity have caused it to be replaced with other substances in laxatives. There is no health hazard from the minute quantities used in titrations.