Final answer:
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.