Calculate the \( \mathrm{pH} \) of a solution prepared by mixing \( 50.0 \mathrm{~mL} \) of \( 0...

Calculate the \( \mathrm{pH} \) of a solution prepared by mixing \( 50.0 \mathrm{~mL} \) of \( 0.200 \mathrm{M} \mathrm{HC}_{2} \mathrm{H}_{3} \mathrm{O}_{2} \) and \( 50.0 \mathrm{~mL} \) of \( 0.100 \)
\[
\mathrm{M} \mathrm{NaOH} .\left[\mathrm{K}_{\mathrm{a}\left(\mathrm{CH}_{3} \mathrm{COOH}\right)}=1.8 \times 10^{-5}\right]
\]