Question

Consider the galvanic cell based on the following half-reactions:

Zn²⁺ + 2e- -> Zn E= -0.76 V
Fe²⁺ + 2e- -> Fe E= -0.44 V
Determine the overall cell reaction and calculate E knot cell.

Answer 1

The overall cell reaction for the galvanic cell based on the zinc and iron half-reactions is Zn(s) + Fe²⁴(aq) → Zn²⁴(aq) + Fe(s), and the standard cell potential (E⁰ cell) is calculated to be 0.32 V.

Step-by-step explanation:

The student has asked about determining the overall cell reaction and calculating the standard cell potential (E⁰ cell) for a galvanic cell based on the provided half-reactions for zinc and iron:

• Zn²⁴ + 2e⁻ → Zn E⁰= -0.76 V
• Fe²⁴ + 2e⁻ → Fe E⁰= -0.44 V

To find the overall reaction, we need to combine these two half-reactions. Since the zinc half-reaction has a more negative E⁰ value, it will act as the anode and undergo oxidation, while the iron will be the cathode and undergo reduction:

• Zn → Zn²⁴ + 2e⁻ (oxidation at anode)
• Fe²⁴ + 2e⁻ → Fe (reduction at cathode)

The overall reaction is then:

Zn(s) + Fe²⁴(aq) → Zn²⁴(aq) + Fe(s)

To calculate the standard cell potential, we use:

E⁰ cell = E⁰ cathode - E⁰ anode

Plugging in the values we get:

E⁰ cell = (-0.44 V) - (-0.76 V) = 0.32 V

So, the standard cell potential for this galvanic cell is 0.32 V.