DP Chemistry (last assessment 2024)
Question 21M.2.hl.TZ2.4e
| Date | May 2021 | Marks available | [Maximum mark: 3] | Reference code | 21M.2.hl.TZ2.4e |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Sketch | Question number | e | Adapted from | N/A |
e.
[Maximum mark: 3]
21M.2.hl.TZ2.4e
Organic chemistry can be used to synthesize a variety of products.
(e)
Sketch the mechanism for the reaction of 2-methylbut-2-ene with hydrogen bromide using curly arrows.
[3]
Markscheme
Alternative 1
Penalize incorrect bond e.g., -CH-H3C or –CH3C only once in the paper.
Alternative 2
curly arrow going from C=C to H of HBr AND curly arrow showing Br leaving ✓
representation of carbocation ✓
curly arrow going from lone pair/negative charge on Br− to C+ ✓
