Question

Write the cell notation for an electrochemical cell consisting of an anode where Cr 2+

(aq) is oxidized to Cr 3+
(aq) at a platinum electrode and a cathode where Fe 3+
(aq) is reduced to Fe 2+
(aq) at a platinum electrode. Assume all aqueous solutions have a concentration of 1 mol/L and gases have a pressure of 1 bar.

Answer 1

The electrochemical cell consisting of a Cr2+ to Cr3+ oxidation at the anode and a Fe3+ to Fe2+ reduction at the cathode with platinum electrodes is represented as Pt(s) | Cr2+(aq) → Cr3+(aq) || Fe3+(aq) → Fe2+(aq) | Pt(s) in cell notation.

Step-by-step explanation:

To write the cell notation for an electrochemical cell with the given components, we have to follow the conventional representation of an electrochemical cell where the anode (oxidation half-reaction) is written first, followed by the cathode (reduction half-reaction). Since all reactions occur in aqueous solutions with platinum as the inert electrode, the cell notation is as follows:

Cr(s) | Cr2+(aq) || Cr3+(aq) | Pt(s) | Fe3+(aq) || Fe2+(aq) | Pt(s)

However, given the information provided in the question, the correct representation of the cell notation is:

Pt(s) | Cr2+(aq) → Cr3+(aq) || Fe3+(aq) → Fe2+(aq) | Pt(s)

Oxidation occurs at the anode where Cr2+ is oxidized to Cr3+, while reduction takes place at the cathode where Fe3+ is reduced to Fe2+. Platinum electrodes serve as inert conductors.

Answer 2

The cell notation for the electrochemical cell is Cr | Cr3+(aq) || Fe3+(aq) | Fe2+(aq) | Pt.

Step-by-step explanation:

The cell notation for the electrochemical cell described can be written as:

Cr | Cr3+(aq) || Fe3+(aq) | Fe2+(aq) | Pt

The anode reaction is Cr(s) → Cr3+(aq) + 3e- and the cathode reaction is Fe3+(aq) + e- → Fe2+(aq).