Question

If an acidic indicator Hlnlonises as $H\ln$ $H^{+} +$ln- .To which maximum pH value its solution has distinct colour characteristic of Hln.

• A. $pK_{\ln}$
• B. $pK_{\ln}$
• C. $pK_{\ln}$
• D. 7

Answer 1

Answer: (B)

$pK_{\ln}$

Answer 2

For colour characteristic of H indicator

$pH = pK_{In} - \log\frac{\left\lbrack H_{\ln}\lbrack\rbrack \right\rbrack}{\left\lbrack \ln^{-}{} \right\rbrack}$

$pH = pK\ln \pm 1$