info@clay6.com
+91-9566306857
(9am to 6pm)
logo

Ask Questions, Get Answers

X
Want help in doing your homework? We will solve it for you. Click to know more.
 
Home  >>  JEEMAIN and NEET  >>  Chemistry  >>  Equilibrium

The rapid change of $pH$ near the stoichiometric point of an acid-base titration is the basis of indicator detection. $pH$ of the solution is related to ratio of the concentration of the conjugated acid(HIn) and base (In) form of the indicator by the expression

(a) $log \frac{[In^-]}{[HIn]} = pH - pK_{In}$

(b) $log \frac{[In^-]}{[HIn]} = pH_{In} - pH$

(c) $log \frac{[HIn]}{[In^-]} = pK_{In} - pH$

(d) $log \frac{[HIn]}{[In^-]} = pH - pK_{In}$

1 Answer

Need homework help? Click here.
Answer: $log \frac{[In^-]}{[HIn]} = pH - pK_{In}$
 
$HIn \rightleftharpoons H^+ + In^-$
 
$K_{In} = \frac{[H^+][In^-]}{[HIn]}$
 
Taking logarithm on both sides we get,
$-log K_{In} = -log [H^+] - log \frac{[In^-]}{[HIn]}$
$\Rightarrow pK_{In} = pK_a - log \frac{[In^-]}{[HIn]}$
$\Rightarrow$ $log \frac{[In^-]}{[HIn]} = pH - pK_{In}$

 

answered Nov 27, 2013 by mosymeow_1
 

Related questions

...