The standard reduction potentials for tin and silver half-cells are given below: \text{Sn}… — JAMB UTME

The standard reduction potentials for tin and silver half-cells are given below:

\text{Sn}^{2+}(aq) + 2e^- \rightarrow \text{Sn}(s) \quad E^\circ = -0.14\text{ V}

\text{Ag}^+(aq) + e^- \rightarrow \text{Ag}(s) \quad E^\circ = +0.80\text{ V}

What is the standard cell potential (

E^\circ_{\text{cell}}

) for the overall redox reaction:

\text{Sn}(s) + 2\text{Ag}^+(aq) \rightarrow \text{Sn}^{2+}(aq) + 2\text{Ag}(s)

+0.94\text{ V}

In the given cell reaction, silver ions undergo reduction at the cathode (

E^\circ = +0.80\text{ V}

) while tin metal undergoes oxidation at the anode (

E^\circ = -0.14\text{ V}

). The standard cell potential is calculated using

E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}} = +0.80\text{ V} - (-0.14\text{ V}) = +0.94\text{ V}

. Because

E^\circ

values are intensive properties, the stoichiometric multiplier for the silver half-reaction does not scale its potential value.

Identify the reduction and oxidation half-reactions from the given reaction equation.

Tin metal (

\text{Sn}

) is oxidized to

\text{Sn}^{2+}

at the anode, while silver ions (

\text{Ag}^+

) are reduced to silver metal at the cathode.

Oxidation occurs at the anode (loss of electrons) and reduction occurs at the cathode (gain of electrons).

Apply the formula for standard cell potential

E^\circ_{\text{cell}} = E^\circ_{\text{cathode}} - E^\circ_{\text{anode}}

E^\circ_{\text{cell}} = (+0.80\text{ V}) - (-0.14\text{ V}) = +0.80\text{ V} + 0.14\text{ V} = +0.94\text{ V}

Standard electrode potentials are intensive properties and are not multiplied by stoichiometric coefficients.

Calculation of Standard Cell Potential and Reaction Spontaneity

Question