DP Chemistry (last assessment 2024)
Question 19M.2.sl.TZ2.a(i)
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.sl.TZ2.a(i) |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Distinguish | Question number | a(i) | Adapted from | N/A |
a(i).
[Maximum mark: 1]
19M.2.sl.TZ2.a(i)
Carbonated water is produced when carbon dioxide is dissolved in water under pressure.
The following equilibria are established.
Carbon dioxide acts as a weak acid.
Distinguish between a weak and strong acid.
Weak acid:
Strong acid:
[1]
Markscheme
Weak acid: partially dissociated/ionized «in solution/water»
AND
Strong acid: «assumed to be almost» completely/100 % dissociated/ionized «in solution/water» [✔]
Examiners report
It was rather disappointing that less than 70 % of the candidates could distinguish between weak and strong acids. Many candidates referred to pH differences.
