Em tham khảo nha:
\(\begin{array}{l}
2Na + 2{H_2}O \to 2NaOH + {H_2}\\
{n_{Na}} = \dfrac{{2,3}}{{23}} = 0,1\,mol\\
{n_{NaOH}} = {n_{Na}} = 0,1\,mol\\
{C_M}NaOH = \dfrac{{0,1}}{{0,12}} = 0,833M\\
{\rm{[N}}{{\rm{a}}^ + }{\rm{]}} = {\rm{[O}}{{\rm{H}}^ - }{\rm{]}} = {C_M}NaOH = 0,833M
\end{array}\)