Larutan Penyangga Persiapan Ulangan 2

Jawab: A

Campuran larutan asam asetat (CH₃COOH) dan natrium asetat (CH₃COONa) akan membentuk larutan penyangga asam.

\begin{equation*}
\begin{split}
[\ce{H+}] & = \text{Ka} \:.\: \frac {\ce{mol CH3COOH}}{\ce{mol CH3COO-}} \\\\
[\ce{H+}] & = 10^{-5} \:.\: \frac {0,1 \:.\: 0,1}{\dfrac {0,82}{82}} \\\\
[\ce{H+}] & = 10^{-5} \:.\: \frac {0,01}{0,01} \\\\
[\ce{H+}] & = 10^{-5}
\end{split}
\end{equation*}

\begin{equation*}
\begin{split}
\ce{pH & = - \log [H+]} \\\\
\ce{pH & = - \log [10^{-5}]} \\\\
\ce{pH & = 5}
\end{split}
\end{equation*}