DP Chemistry (last assessment 2024)
Question 21M.2.hl.TZ1.d
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.hl.TZ1.d |
| Level | hl | Paper | 2 | Time zone | TZ1 |
| Command term | Deduce | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 2]
21M.2.hl.TZ1.d
Magnetite, Fe3O4, is another ore of iron that contains both Fe2+ and Fe3+.
A voltaic cell is set up between the Fe2+ (aq) | Fe (s) and Fe3+ (aq) | Fe2+ (aq) half-cells.
Deduce the equation and the cell potential of the spontaneous reaction. Use section 24 of the data booklet.
[2]
Markscheme
Equation:
2Fe3+(aq) + Fe(s) → 3Fe2+(aq) ✔
Cell potential:
«+0.77 V − (−0.45 V) = +»1.22 «V» ✔
Do not accept reverse reaction or equilibrium arrow.
Do not accept negative value for M2.