the pH of an aqueous solution with [paba] = 0. 030 m and ka = 2. 2 × 10⁻⁵
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
[tex]\rm K_{a}= \dfrac{[H^{+}][H_{2}NC_{6}H_{4}COO^{-} ]}{[H_{2}NC_{6}H_{4}COOH]}[/tex]
= 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
