the pH of an aqueous solution with [paba] = 0. 030 m and ka = 2. 2 × 10⁻⁵
What is pH ?
pH is a measure of how acidic/basic water is.
The range goes from 0 - 14, with 7 being neutral.
pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water.
H₂NC₆H₄COOH ----> H₂NC₆H₄COO⁻ + H⁺
0.030M 0 0
0.030-x x x
![\rm K_(a)= ([H^(+)][H_(2)NC_(6)H_(4)COO^(-) ])/([H_(2)NC_(6)H_(4)COOH])](https://img.qammunity.org/2023/formulas/chemistry/high-school/jb6w11ygvol62a8u04vjeo5f1iahb4n67x.png)
= x² / 0.030-x
x = 8.01 * 10⁻⁴
[H⁺] = x = 8.01 * 10⁻⁴
pH = -log[ H⁺]
=-log[ 8.01 * 10⁻⁴]
pH = 3.09
Therefore the pH of an aqueous solution with [paba] = 0. 030 m and ka = 2. 2 × 10⁻⁵