Answer: The total reduction potential of the cell is -3.89 V.
Step-by-step explanation:
We are given:
- Reduction of lithium follows the reaction:

The standard reduction potential for this is -3.04 V
- Oxidation of mercury follows the reaction:

The standard reduction potential for this is -0.85 V
The cell formed by these half reactions is:

The cell potential,

![E^o_(cell)=[-0.85+(-3.04)]=-3.89V](https://img.qammunity.org/2020/formulas/chemistry/high-school/bfeidxea8370kl4jcto3s82yp9dj4h32mg.png)
Hence, the total reduction potential of the cell is -3.89 V.