Determine potential for the cell Pt | array c Fe ^ 2+ Fe ^ 3+ array | | array c Cr _2…

CHEMISTRY · Subjective · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry

Problem

Determine potential for the cell

\text{Pt} \left| \begin{array}{c} \text{Fe}^{2+} \\ \text{Fe}^{3+} \end{array} \right| \left| \begin{array}{c} \text{Cr}_2\text{O}_7^{2-}, \text{Cr}^{3+}, \text{H}^+ \end{array} \right| \text{Pt}

in which

[\text{Fe}^{2+}]

and

[\text{Fe}^{3+}]

are 0.5M and 0.75M respectively and

[\text{Cr}_2\text{O}_7^{2-}]

[\text{Cr}^{3+}]

and

[\text{H}^+]

are 2M, 4M and 1M respectively. Given,

\text{Fe}^{3+} + e \longrightarrow \text{Fe}^{2+}

E^\circ = 0.770\text{V}

14\text{H}^+ + 6e + \text{Cr}_2\text{O}_7^{2-} \longrightarrow 2\text{Cr}^{3+} + 7\text{H}_2\text{O}

E^\circ = 1.35\text{V}