DP Chemistry (first assessment 2025)
Question EXM.2.HL.TZ0.4
| Date | May Example question | Marks available | [Maximum mark: 2] | Reference code | EXM.2.HL.TZ0.4 |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Suggest | Question number | 4 | Adapted from | N/A |
4.
[Maximum mark: 2]
EXM.2.HL.TZ0.4
Benzene, C6H6, can undergo electrophilic substitution reactions that proceeds slowly. Suggest why methylbenzene, C7H6, proceeds much faster.
[2]
Markscheme
methyl/alkyl «group» positive inductive effect ✓
stabilises intermediate carbocation
OR
increased electron density in ring ✓
Allow appropriate diagrams for M1
Syllabus sections
Reactivity 3. What are the mechanisms of chemical change? » Reactivity 3.4—Electron-pair sharing reactions » Reactivity 3.4.13—Electrophilic substitution reactions include the reactions of benzene with electrophiles. Describe and explain the mechanism of the reaction between benzene and a charged electrophile, E+.