Calculate the Reduction Potential for the Half Cell of Cl⁻ | Cl₂

What is the balanced half-reaction for the reduction of chlorine gas to chloride ions?

A) Cl⁻ + e⁻ ⟶ Cl₂
B) Cl₂ + e⁻ ⟶ Cl⁻
C) Cl₂ + 2e⁻ ⟶ 2Cl⁻
D) 2Cl⁻ ⟶ Cl₂ + 2e⁻

How can we calculate the actual reduction potential at 25°C for the given half cell conditions?

Answer:

The balanced half-reaction for the reduction of chlorine gas to chloride ions is Cl₂ + 2e⁻ ⟶ 2Cl⁻ with a standard reduction potential (E⁰) of 1.36 V.

To calculate the actual reduction potential at 25°C for the given conditions of Cl⁻ at 1.2 M and Cl₂ at 3.6 atm, we can use the Nernst equation. The equation is:

E = E° - (RT/nF)ln(Q)

Where:

E is the actual reduction potential

E° is the standard reduction potential (1.36 V in this case)

R is the gas constant (8.314 J/mol∙K)

T is the temperature in Kelvin (298 K for 25°C)

n is the number of electrons transferred (2 for this reaction)

F is the Faraday constant (96485 C/mol)

Q is the reaction quotient

For this half-cell reaction, the reaction quotient (Q) is calculated as the partial pressure of Cl₂ divided by the concentration of Cl⁻ squared, based on the reaction stoichiometry.

After determining Q, you can substitute the values into the Nernst equation to find the actual reduction potential for the given conditions.