- #1

Huzaifa

- 40

- 2

$$

\begin{aligned}

\mathrm{HA}+& \mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{A}^{-}+\mathrm{H}_{3} \mathrm{O}^{+} \\

K_{\mathrm{a}} &=\frac{\left[\mathrm{A}^{-}\right]\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]}{[\mathrm{HA}]} \\

K_{\mathrm{a}} &=\left[\mathrm{H}_{3} \mathrm{O}^{+}\right] \times \frac{\left[\mathrm{A}^{-}\right]}{[\mathrm{HA}]} \\

K_{\mathrm{a}} &=\left[\mathrm{H}_{3} \mathrm{O}^{+}\right] \times \frac{[\text { conjugate base }]}{[\text { acid }]} \\

-\log _{10} \mathrm{~K}_{\mathrm{a}} &=-\log _{10}\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]-\text {log }_{10} \frac{[\text { conjugate base }]}{[\text { acid }]} \\

\mathrm{pK}_{\mathrm{a}} &=\mathrm{pH}-\log _{10} \frac{[\text { conjugate base }]}{[\text { acid }]} \\

\mathrm{pH} &=\mathrm{pK}_{\mathrm{a}}+\log _{10} \frac{[\text { conjugate base }]}{[\text { acid }]}

\end{aligned}

$$