Calculate The E Cell for The Following Equation Pbs

What is E cell?

The E cell, or cell potential, is the voltage difference between the anode and cathode in an electrochemical cell. It determines the direction and magnitude of electron flow in the cell. The standard cell potential (E°cell) is the potential when all reactants are in their standard states (1 M concentration, 1 atm pressure, and pure solids).

The actual cell potential (Ecell) depends on the concentrations of the reactants and products, as described by the Nernst equation:

How to calculate E cell

To calculate the E cell for a given redox reaction:

1. Write the balanced redox reaction
2. Determine the standard cell potential (E°cell) from a standard table
3. Calculate the reaction quotient (Q) using the concentrations of reactants and products
4. Apply the Nernst equation to find Ecell

The calculator on this page automates these steps for you.

Example calculation

Consider the following reaction:

Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)

Given:

• E°cell = +0.76 V
• [Cu²⁺] = 0.1 M
• [Zn²⁺] = 0.01 M
• Temperature = 25°C (298 K)
• n = 2 electrons

The reaction quotient Q is:

Q = [Zn²⁺]/[Cu²⁺] = 0.01/0.1 = 0.1

Using the Nernst equation:

Ecell = 0.76 - (0.0257 V) * log(0.1) = 0.76 + 0.052 = 0.812 V

Interpretation of results

The calculated E cell value indicates:

• If Ecell > 0: The reaction is spontaneous (energy is released)
• If Ecell = 0: The reaction is at equilibrium
• If Ecell < 0: The reaction is non-spontaneous (energy is required)

A positive E cell value means the cell can do work, while a negative value means an external power source is needed to drive the reaction.