Calculate The E Cell for The Following Equation Cu S

The E cell (cell potential) is a measure of the tendency of a chemical reaction to occur spontaneously. For the equation Cu(s), we can calculate the standard cell potential using standard electrode potentials.

What is E cell?

The E cell, or cell potential, is the difference in electrical potential between the anode and cathode in an electrochemical cell. It determines the direction and spontaneity of a redox reaction. The standard cell potential (E°cell) is calculated using standard electrode potentials (E°) for the half-reactions involved.

For a spontaneous reaction (E cell > 0), the reaction will proceed as written. For a non-spontaneous reaction (E cell < 0), the reaction will not occur as written.

How to calculate E cell

To calculate the standard cell potential (E°cell) for a redox reaction, you need the standard electrode potentials for the oxidation and reduction half-reactions. The formula is:

E°cell = E°cathode - E°anode

Where:

E°cell is the standard cell potential (V)
E°cathode is the standard reduction potential for the reduction half-reaction (V)
E°anode is the standard reduction potential for the oxidation half-reaction (V)

For the equation Cu(s), the standard electrode potential is 0.34 V (vs. SHE).

Standard electrode potentials

Standard electrode potentials are measured under standard conditions (1 M concentration, 298 K, 1 atm pressure). Here are some common standard electrode potentials:

Half-reaction	E° (V vs. SHE)
Cu²⁺ + 2e⁻ → Cu(s)	0.34
Zn²⁺ + 2e⁻ → Zn(s)	-0.76
Fe²⁺ + 2e⁻ → Fe(s)	-0.44
Ag⁺ + e⁻ → Ag(s)	0.80

Example calculation

Let's calculate the standard cell potential for the reaction:

Cu(s) + Ag⁺ → Cu²⁺ + Ag(s)

This is a displacement reaction where copper displaces silver from solution.

Example Input

Cathode half-reaction: Ag⁺ + e⁻ → Ag(s) (E° = 0.80 V)

Anode half-reaction: Cu(s) → Cu²⁺ + 2e⁻ (E° = 0.34 V)

Calculation: E°cell = E°cathode - E°anode = 0.80 V - 0.34 V = 0.46 V

Result: The standard cell potential is 0.46 V

The positive value indicates the reaction is spontaneous as written.

FAQ

What is the difference between E cell and E°cell?

E cell is the actual cell potential under specific conditions, while E°cell is the standard cell potential under standard conditions (1 M concentration, 298 K, 1 atm pressure).

How do temperature and concentration affect E cell?

Temperature affects electrode potentials through the Nernst equation. Concentration changes affect the actual cell potential (E cell) but not the standard cell potential (E°cell).

What is the standard hydrogen electrode (SHE)?

The standard hydrogen electrode (SHE) is the reference electrode with a defined potential of 0 V at standard conditions. All other electrode potentials are measured relative to SHE.