Henderson-Hasselbach Equation

$\mathrm{pH}=\mathrm{p}{\mathrm{K}}_{\mathrm{a}}+\log \left(\frac{[A^{-}]}{[HA]}\right)$

• Works when inside the buffer region of a titration ($\pm 1\mathrm{pH}$ of the $\mathrm{pKa}$)

$\{\begin{array}{l}\nabla \times \vec{E}=-\frac{\partial \vec{B}}{\partial t}\\ \nabla \times \vec{H}=\overrightarrow{J_v}+\frac{\partial \vec{D}}{\partial t}\\ \nabla \cdot \vec{D}={\rho }_v\\ \nabla \cdot \vec{B}=0\end{array},\{\begin{array}{l}\vec{D}=ϵ\vec{E}\\ \vec{B}=\mu \vec{H}\\ \overrightarrow{J_v}=\sigma \vec{E}\end{array}$