DP Chemistry (last assessment 2024)
Question 21M.2.hl.TZ2.f
| Date | May 2021 | Marks available | [Maximum mark: 2] | Reference code | 21M.2.hl.TZ2.f |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | f | Adapted from | N/A |
f.
[Maximum mark: 2]
21M.2.hl.TZ2.f
Organic chemistry can be used to synthesize a variety of products.
Explain why the major organic product is 2-bromo-2-methylbutane and not 2-bromo-3-methylbutane.
[2]
Markscheme
«2-bromo-2-methylbutane involves» formation of more stable «tertiary» carbocation/intermediate
OR
«2-bromo-3-methylbutane involves» formation of less stable «secondary» carbocation/intermediate ✓
«intermediate» more stable due to «increased positive» inductive/electron-releasing effect of extra –R/alkyl group/–CH3/methyl ✓
Do not award marks for quoting Markovnikov’s rule without any explanation.
