First slide

Acidic buffer

Question

An indicator has ${pK}_{In} = 5.3 .$ In a certain titration, this indicator is found to be 20% ionized in its acid form. Thus, pH of the solution is

Moderate

A

4.7
B

5.3
C

5.9
D

6.2

Solution

$\underset{Acid form}{HIn} ⇌ \underset{Basic}{H^{+}} + \underset{form}{{In}^{-}}$
Thus, acid form [HIn] = 0.80 M
$[{In}^{-}] = 0.20 M pH = {pK}_{In} + \log \frac{[{In}^{-}]}{[HIn]} = 5.3 + \log \frac{0.2}{0.8} = 5.3 + \log \frac{1}{4} = 5.3 - 0.60 = 4.7$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App