Question
The indicator constant for an acidic indicator, HIn is 5 × 10−6 M. This indicator appears only in the colour of acidic form when $\frac{\left\lbrack \ln^{-}{} \right\rbrack}{\left\lbrack Hln\lbrack\rbrack \right\rbrack\frac{1}{20}}$and it appears only in the colour of basic form when $\frac{\left\lbrack Hln\lbrack\rbrack \right\rbrack}{\left\lbrack \ln^{-}{} \right\rbrack\frac{1}{40}}$. The pH range of indicator is (log 2 = 0.3)
Options
Solution
$P^{K_{\ln}\log K_{\log\left( 5 \times 10^{- 6} \right)\ln}}$
Now, $P^{H} = P^{K_{\ln}\log\frac{\left\lbrack \ln^{-}{} \right\rbrack}{\left\lbrack Hln\lbrack\rbrack \right\rbrack}}$
Only for acidic form, $P^{H} \leq \left( 5.3 + \log\frac{1}{20} \right) = 4.0$
Only for basic form, $P^{H} \geq \left( 5.3 + \log 40 \right) = 6.9$
Create a free account to view solution
View Solution Free