DP Chemistry (last assessment 2024)
Question 21M.2.hl.TZ2.d(i)
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.hl.TZ2.d(i) |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Sketch | Question number | d(i) | Adapted from | N/A |
d(i).
[Maximum mark: 2]
21M.2.hl.TZ2.d(i)
Ethanol and methanoic acid are important industrial products.
Sketch the titration curve of methanoic acid with sodium hydroxide, showing how you would determine methanoic acid pKa.
[2]
Markscheme
increasing S-shape pH curve ✓
pKa: pH at half neutralization/equivalence ✓
M1: Titration curve must show buffer region at pH <7 and equivalence at pH >7.
Ignore other parts of the curve, i.e., before buffer region, etc.
Accept curve starting from where two axes meet as pH scale is not specified.