Standard electrode potential for Sn⁴⁺ / Sn²⁺ couple is + 0.15 V and that for the Cr³⁺ / Cr couple is – 0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be

Standard electrode potentials:

• $E$^°_{Sn^{4+}/Sn^{2+}} = +0.15 \text{ V}
• $E$^°_{Cr^{3+}/Cr} = -0.74 \text{ V}

Steps:

1. Identify the anode and cathode:

The reduction potential is higher for the $Sn^\{4+\}/Sn^\{2+\}$ couple (+0.15 V), so it acts as the cathode (reduction occurs here).

The $Cr^\{3+\}/Cr$ couple has a lower reduction potential (-0.74 V), so it acts as the anode (oxidation occurs here).

1. Calculate the cell potential:

The formula for cell potential is:

E^°_{cell} = E^°_{cathode} - E^°_{anode}

Substitute the values:

E^°_{cell} = (+0.15) - (-0.74)

E^°_{cell} = +0.15 + 0.74 = +0.89 \text{ V}

Final Answer:

The cell potential is: +0.89 V