Question
Question: K<sub>b</sub> of an acid-base indicator H In is 10<sup>–9</sup>. The pH at which its 10<sup>–3</sup>...
Kb of an acid-base indicator H In is 10–9. The pH at which its 10–3 (M) solution shows the colour change
A
9
B
7
C
5
D
3
Answer
5
Explanation
Solution
KaKb = 10–14
or Ka = Kin = 10–5
\ [H+] = 10–5
or pH = 5