Chemistry Forum

The indicator dinitrophenol is an acid with a \(K_a \) of 1.1 × 10⁻⁴. In a 1.0 × 10⁻⁴ solution, it is colorless in acid and yellow in base.

Calculate the pH range over which it goes from 10% ionized (colorless) to 90% ionized (yellow).

What your ideas. What is the dissociation equation?

Actually i don't understand the meaning of 10% ionized (colorless) to 90% ionized(yellow).

I am working on this question. I want to read some chemistry articles on this topic and want to view some videos, if available on this topic.

It means HInd. => H+ + Ind.- if 10% is on the right side its colourless, if the dissociation is 90 % then its yellow.
It is a change from 10 Ind.- to 90 HInd. to 90Ind.- to 10 HInd.

Develop K =