DP Chemistry (first assessment 2025)
Question 19M.1A.SL.TZ2.23
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.SL.TZ2.23 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 23 | Adapted from | N/A |
23.
[Maximum mark: 1]
19M.1A.SL.TZ2.23
The following reaction occurs in a voltaic (galvanic) cell.
Mg (s) + 2Ag+ (aq) → Mg2+ (aq) + 2Ag (s)
Which reaction takes place at each electrode?
[1]
Markscheme
C
Examiners report
The question about electrode reactions discriminated well between high scoring and low scoring candidates. 70 % of the candidates selected the correct electrode reactions given the cell reaction. The most commonly chosen distractor had the same reactions at the opposite electrodes.
Syllabus sections
Reactivity 3. What are the mechanisms of chemical change? » Reactivity 3.2—Electron transfer reactions » Reactivity 3.2.5—Oxidation occurs at the anode and reduction occurs at the cathode in electrochemical cells. Identify electrodes as anode and cathode, and identify their signs/polarities in voltaic cells and electrolytic cells, based on the type of reaction occurring at the electrode.