# How does pka relate to mmhg?

Are you asking how $p {K}_{a}$ relates to pressure measurement?
$p {K}_{a}$ relates to an equilibrium phenomenon; $m m$ $H g$ is a measurement of pressure. Most measurements of $p {K}_{a}$ specify standard conditions, i.e. $1$ $a t m$ ($=$ $760$ $m m$ $H g$), and $298$ $K$, but there is no real relationship between acidity and pressure.