# How can I calculate pH of NaOH?

Dec 5, 2014

Assuming that you either start with, or can determine a molar concentration for $N a O H$, the easiest way to get to $p H$ is by calculating $p O H$.

$N a O H$ is a strong base, which means it dissociates completely

$N a O H \left(a q\right) + {H}_{2} O \left(a q\right) \iff N {a}^{+} \left(a q\right) + O {H}^{-} \left(a q\right)$

The concentrations of $N {a}^{+}$ and $O {H}^{-}$ are equal to the intial concentration of $N a O H$, let's say $X$. You can now determine $p O H$ by using

$p O H = - \log \left(X\right)$, which then gets you to

$p H = 14 - p O H$