DP Chemistry (first assessment 2025)
Question 19N.1B.SL.TZ0.2a(ii)
| Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.1B.SL.TZ0.2a(ii) |
| Level | SL | Paper | 1B | Time zone | TZ0 |
| Command term | Determine | Question number | a(ii) | Adapted from | N/A |
a(ii).
[Maximum mark: 2]
19N.1B.SL.TZ0.2a(ii)
(a(ii))
Determine the change in the average oxidation state of carbon.
From ethanol to ethanal:
From ethanol to carbon dioxide:
[2]
Markscheme
From ethanol to ethanal:
−2 to −1
OR
+1/increases by 1 ✔
NOTE: Do not accept “2− to 1−”.
From ethanol to carbon dioxide:
−2 to +4
OR
+6/increases by 6 ✔
NOTE: Do not accept “2− to 4+”.
Do not penalize incorrect notation twice.
Penalize incorrect oxidation state value of carbon in ethanol once only.
