A galvanic cell is constructed from the following two half-reactions

CHEMISTRY · Single correct · A Level · Chemistry · Electrode potentials · Electrode potentials

Problem

A galvanic cell is constructed from the following two half-reactions, each operating under standard conditions: 1.

\text{MnO}_4^-(aq) + 8\,\text{H}^+(aq) + 5\,e^- \rightarrow \text{Mn}^{2+}(aq) + 4\,\text{H}_2\text{O}(l), \; E^\circ = +1.51\,\text{V}

\text{Sn}^{4+}(aq) + 2\,e^- \rightarrow \text{Sn}^{2+}(aq), \; E^\circ = +0.15\,\text{V}

The cell is assembled so that

\text{Sn}^{2+}

is oxidized to

\text{Sn}^{4+}

and

\text{MnO}_4^-

is reduced to

\text{Mn}^{2+}

. Which of the following gives the value of

E^\circ_{\text{cell}}

and correctly predicts whether the overall reaction is spontaneous under standard conditions? (a)

E^\circ_{\text{cell}} = +1.66\,\text{V};

the reaction is spontaneous. (b)

E^\circ_{\text{cell}} = -1.36\,\text{V};

the reaction is non-spontaneous. (c)

E^\circ_{\text{cell}} = +1.36\,\text{V};

the reaction is spontaneous. (d)

E^\circ_{\text{cell}} = +1.36\,\text{V};

the reaction is non-spontaneous.