Answer
pH = 3.32
Explanation
Given
Acid dissociation of carbonic acid (Ka) = 4.4x10^-7
Concentration = 0.530 M
Solution
The carbonic acid dissociates into:
[tex]\begin{gathered} H_2CO_3\rightarrow\text{ H}^{+\text{ }}+\text{ HCO3}^- \\ \end{gathered}[/tex][tex]\begin{gathered} Ka\text{ = }\frac{[H^+][A^-]}{[HA]} \\ [H^+]\text{ = \lbrack A}^-] \\ Ka\text{ x \lbrack HA\rbrack= \lbrack H}^+]^2 \\ 4.4\text{ x 10}^{-7}\text{ x 0.530 = \lbrack H}^+]^2 \\ 2.332\text{ x 10}^{-7}\text{ = \lbrack H}^+]^2 \\ 4.816\text{ x 10}^{-4}\text{ = \lbrack H}^+] \\ \\ \end{gathered}[/tex]Now we can calculate the pH
pH = -log[H+]
pH = -log[4.816x10^-4]
pH = 3.32