Tetapan Kesetimbangan Kp

Reaksi kesetimbangan

\begin{equation*}
\begin{array}
& & \ce{2 H2 (g)} & + & \ce{O2 (g)} & \ce{<=>} & \ce { 2 H2O (g)}  \\\\
\text{Setimbang} & 0,6 & & 0,4 && 0,8
\end{array}
\end{equation*}

Tekanan parsial masing-masing gas

\(P \: _{\ce{H2}} = \dfrac{0,6}{0,6 + 0,4 + 0,8} \times 10 \text{ atm } = \dfrac {30}{9} \text{ atm }\)

\(P \: _{\ce{O2}} = \dfrac{0,4}{0,6 + 0,4 + 0,8} \times 10 \text{ atm } = \dfrac {20}{9} \text{ atm }\)

\(P \: _{\ce{H2O}} = \dfrac{0,8}{0,6 + 0,4 + 0,8} \times 10 \text{ atm } = \dfrac {40}{9} \text{ atm }\)

Tetapan kesetimbangan Kp

\begin{equation*}
\begin{split}
Kp & = \frac {[P \: _{\ce{H2O}}]^2}{[P \: _{\ce{H2}}]^2 \:.\: [P \: _{\ce{O2}}]} \\\\
Kp & = \frac {[\frac {40}{9}]^2}{[\frac {30}{9}]^2 \:.\: [\frac {20}{9}]} \\\\
Kp & = \left[\frac {40}{9}\right]^2 \:.\: \left[\frac {9}{30}\right]^2 \:.\: \left[\frac {9}{20}\right] \\\\
Kp & = \frac {[40]^2 \:.\: [9]}{[30]^2 \:.\: [20]} \\\\
Kp & = \frac {4}{5}
\end{split}
\end{equation*}