# What is the pH of a 0.050 M NaOH solution?

Jan 16, 2017

#### Explanation:

NaOH is a strong base, meaning it will dissociate basically completely in solution to form $N {a}^{+}$ and $O {H}^{-}$ ions in solution.

One mole of $O {H}^{-}$ ions is created for every mole of NaOH that is dissolved. If it's a .05 M solution of NaOH, then it can also be interpreted to be a .05M solution of $O {H}^{-}$.

$p O H$ (The pH scale for bases) can be found by taking the negative logarithm of $O {H}^{-}$ concentration.

$p O H$ = $- \log \left[.05 M\right]$ = 1.3.

However, we are trying to find $p H$, so we must use the formula
$p O H + p H = 14$.

Now that we know $p O H = 1.3$,
$p H = 14 - 1.3 = 12.7$.