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If very small amount of phenolphthalein ...

If very small amount of phenolphthalein is addded to 0.15 M solution of sodium benzoate , what fraction of the indicator will exist in the coloured form ?
`K_(a("Benzoic acid")) = 6.2 xx10^(-5)`
`K_(w(H_(2)O))= 1xx10^(-14)`
`K_(In("phenolphthalein"))=3.16 xx10^(-10)` .

Text Solution

AI Generated Solution

To solve the problem, we need to find the fraction of phenolphthalein that exists in its colored form when a very small amount is added to a 0.15 M solution of sodium benzoate. We will follow these steps: ### Step 1: Calculate the pH of the sodium benzoate solution Sodium benzoate is a salt that hydrolyzes in water. The pH can be calculated using the formula: \[ \text{pH} = \frac{1}{2} \left( pK_w + pK_a + \log C \right) \] where: ...
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