To indicate the ph of a substance, one can use a dye that is both an acid and that appears as different colors in its protonated and deprotonated forms. suppose that you have a 0.001 m solution

Chemistry
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to indicate the ph of a substance, one can use a dye that is both an acid and that appears as different colors in its protonated and deprotonated forms. suppose that you have a 0.001 m solution of a dye with a pka of 7.2. from the color, the concentration of the protonated form, ha, is 0.0002 m. assume that the remainder of the dye is in the deprotonated form, a−. what is the ph of the solution? give your answer to one decimal place.

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Answer:

[A-]=0.001 M-0.0002 M=0.0008 M

pH = pKa + log( [A-]/[HA] )

pH =7.2+0.6=7.8