Question

What is pH value of 1M NaOH?

Answer 1

1 mole of sodium hydroxide produces 1 mole of $N{a}^{+}$ and 1 mole of $O{H}^{-}$ ions. This means that the concentration of the hydroxide ions will be equal to
$\left[O{H}^{-}\right]=\left[NaOH\right]=0.1M$
We can use this concentration to determine the pOH of the solution
$pOH=-log\left(\right[O{H}^{-}\left]\right)$
pOH=−log(0.1)=1.0
Therefore, the pH of the solution will be equal to
pH = 14−pOH =14−1.0 = 13.0