Ionic EquilibriumMedium
Question
An acid type indicator, HIn differs in colour from its conjugate base (In–). The human eye is sensitive to colour differences only when the ratio [In–]/[HIn] is greater than 10 or smaller than 0.1. What should be the minimum change in the pH of the solution to observe a complete colour change (Ka = 1.0 × 10–5)?
Options
A.0.0
B.1.0
C.2.0
D.5.0
Solution
For complete colour change, PH should change from, $P^{H} \leq \left( P^{K_{a}} + \log\frac{1}{10} \right)\text{ to }P^{H} \geq \left( P^{K_{a}} + \log 10 \right)$and hence, minimum PH change should be of 2.0 units.
Create a free account to view solution
View Solution FreeMore Ionic Equilibrium Questions
A certain mixture of HCl and CH3- COOH is 0.1 M in each of the acids. 20 ml of this solution is titrated against 0.1M Na...Solubility product of a salt AB is 1 × 10-8 in a solution in which th concentration of A+ ions is 10-3 M. The salt ...The pH value of 0.1 M solutions of CH3COONa (I), CH3COOH (II), CH3COONH4 (III), NaOH (IV) and HCl (V) is in the order...Which one of the following is an amphoteric oxide?...The degree of hydrolysis of a salt of weak acid and weak base in its 0.1 M solution is found to be 50%. If the molarity ...