\paragraph{Zadání}
Určete směr oxidačně-redukční reakce \ilm{2\:Fe^{3+} + 2\:I^- \rightleftharpoons 2\:Fe^{2+} + I_2} \\
\begin{tabular}{l>{=}cr}
- \ilm{E^\stdpot(I_2/2I^-)} && \num{+0,57}~\si{\volt} \\
+ \ilm{E^\stdpot(I_2/2I^-)} && \num{+0,54}~\si{\volt} \\
\ilm{E^\stdpot(Fe^{3+}/Fe^{2+})} && \num{+0,77}~\si{\volt}
\end{tabular}
[OH^-] &= \sqrt{K_B c_{HA}} \\
[OH^-] &= \sqrt{\num{2,042e-10} \cdot \num{1,5e-5}} \\
[OH^-] &= \sqrt{\num{3,063e-15}} \\
- [OH^-] &= \num{5,534e-8}\:[\si{\mpdm}] \\
+ [OH^-] &= \SI{5,534e-8}{\mpdm} \\
pOH &= -\log\left(\num{5,534e-8}\right) = \num{7,256} \\
pH &= 14 - \num{7,256} \\
pH &= \num{6,743}
[OH^-] &= \sqrt{K_b c_{HA} + K_W} \\
[OH^-] &= \sqrt{\num{2,042e-10} \cdot \num{1,5e-5} + \num{1e-14}} \\
[OH^-] &= \sqrt{\num{1,306e-14}} \\
- [OH^-] &= \num{1,143}\:[\si{\mpdm}] \\
+ [OH^-] &= \SI{1,143e-7}{\mpdm} \\
pOH &= \num{6,942} \\
- pH &= \num{7,085}
+ pH &= \num{7,058}
\end{align*}
}
\FloatJail{calculation}{Potenciál v ekvivalenci}{
\begin{align*}
E_{ekv} &= \frac{n_1 E_1 + n_2 E_2}{n_1 + n_2} \\
- E_{ekv} &= \frac{6 \cdot \num{1,360} + 2 \cdot \num{0,139}}{1 + 3} \\
+ E_{ekv} &= \frac{6 \cdot \num{1,360} + 2 \cdot \num{0,139}}{2 + 6} \\
E_{ekv} &= \frac{\num{8,438}}{8} \\
E_{ekv} &= \SI{1,055}{\volt}
\end{align*}