Question

Write the cell notation for an electrochemical cell consisting of an anode where Co (s) is oxidized to Co2+ (aq) and a cathode where Fe3+ (aq) is reduced to Fe2+ (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 cell notation for the described electrochemical cell is Co(s) | Co2+(aq, 1 M) || Fe3+(aq, 1 M), Fe2+(aq, 1 M) | Pt(s), with Co being oxidized at the anode and Fe3+ being reduced to Fe2+ at a platinum cathode.

Step-by-step explanation:

The cell notation for an electrochemical cell consisting of a cobalt anode and a platinum cathode, where Co (s) is oxidized to Co2+ (aq) and Fe3+ (aq) is reduced to Fe2+ (aq), is:

• Co(s) | Co2+(aq, 1 M) || Fe3+(aq, 1 M), Fe2+(aq, 1 M) | Pt(s)

In this cell notation, the anode is on the left, which is where oxidation takes place. The oxidation half-reaction is represented by Co (s) being oxidized to Co2+ (aq). On the right side of the cell notation, the reduction half-reaction occurs at the cathode. The inert platinum electrode is used because the redox couple of Fe3+ and Fe2+ does not form a solid electrode. The double vertical lines represent the salt bridge between the two half-cells.

Answer 2

Answer: The cell notation for the given cell will be:
`Co/Co^(2+)(1M,aq.)||Fe^(3+)(1M,aq.)/Fe^(2+)(1M,aq.)|Pt(s)`

Step-by-step explanation:

The half cell reaction follows:

Oxidation half reaction:
`Co(s)\rightarrow Co^(2+)(1M,aq.)+2e^-`

Reduction half reaction:
`Fe^(3+)(1M,aq.)+1e^-\rightarrow Fe^(2+)(1M,aq.)` ( × 2)

Net reaction:
`Co(s)+2Fe^(3+)(1M,aq.)\rightarrow Co^(2+)(1M,aq.)+2Fe^(2+)(1M,aq.)`

Oxidation reaction always occurs at anode.

Cell notation is the representation in which, the anode is written on left hand side followed by its ion with its molar concentration. It is then followed by a salt bridge, which is represented by the symbol "||" . Then the cathodic ion with its molar concentration is written and then the cathode.

Hence, the cell notation for the given cell will be:
`Co/Co^(2+)(1M,aq.)||Fe^(3+)(1M,aq.)/Fe^(2+)(1M,aq.)|Pt(s)`