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Colour change of fluorescein in acidic and basic medium
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Kiele
Colour change of fluorescein in acidic and basic medium
The lactone form is not stable in basic medium, so the cycle opens and gives conjugation to flow and unite all four rings. The problem is you really swithched the acidic and basic forms of fluorescein, so the left one exists at basic pHs (except for the H atom at carboxylate - it goes away), and acid medium favors the existence of the right form.
You may check the forms of phenolphthaleine - they are pretty much the same.
The lactone form is not stable in basic medium, so the cycle opens and gives conjugation to flow and unite all four rings. The problem is you really swithched the acidic and basic forms of fluorescein, so the left one exists at basic pHs (except for the H atom at carboxylate - it goes away), and acid medium favors the existence of the right form. You may check the forms of phenolphthaleine - they are pretty much the same.
Well you might be correct for the basic medium(i checked those phenolphthalein structures) but in the acidic medium it should be the one which is given because I used concentrated acid and when the same amount was added in a test tube containing phenolphthalein, it gave the red colour which has the similar structureMore
well, that changes everything. Then we dont talk about form #2 in your question at all. I believe if you want the structures for this case, youll need to look at structures of phenolphthalein that represent orange and pink colors.More
The lactone form is not stable in basic medium, so the cycle opens and gives conjugation to flow and unite all four rings. The problem is you really swithched the acidic and basic forms of fluorescein, so the left one exists at basic pHs (except for the H atom at carboxylate - it goes away), and acid medium favors the existence of the right form.
You may check the forms of phenolphthaleine - they are pretty much the same.
The lactone form is not stable in basic medium, so the cycle opens and gives conjugation to flow and unite all four rings. The problem is you really swithched the acidic and basic forms of fluorescein, so the left one exists at basic pHs (except for the H atom at carboxylate - it goes away), and acid medium favors the existence of the right form.
You may check the forms of phenolphthaleine - they are pretty much the same.
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