DP Chemistry (first assessment 2025)
Question 22M.1A.HL.TZ2.28
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.HL.TZ2.28 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Deduce | Question number | 28 | Adapted from | N/A |
28.
[Maximum mark: 1]
22M.1A.HL.TZ2.28
How many signals are observed in the 1H NMR spectrum of this compound?
A. 1
B. 2
C. 3
D. 4
[1]
Markscheme
A
Examiners report
The compound used for this 1H NMR question was unfamiliar to the candidates and it was a skeletal formula. They were expected to notice its symmetry and that all H’s had the same chemical environment. The majority of candidates saw only part of this symmetry and decided on two chemical environments. 29% of the candidates obtained the correct answer. Some teachers commented on the difficulty of this question.
Syllabus sections
Structure 3. Classification of matter » Structure 3.2—Functional groups: Classification of organic compounds » Structure 3.2.10—Proton nuclear magnetic resonance spectroscopy (1H NMR) gives information on the different chemical environments of hydrogen atoms in a molecule. Interpret 1H NMR spectra to deduce the structures of organic molecules from the number of signals, the chemical shifts, and the relative areas under signals (integration traces).