DP Chemistry (first assessment 2025)
Question 22M.1A.HL.TZ2.40
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.HL.TZ2.40 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Interpret | Question number | 40 | Adapted from | N/A |
40.
[Maximum mark: 1]
22M.1A.HL.TZ2.40
Given equimolar concentrations, which substance would produce the strongest signal in a 1H NMR spectrum?
A. (CH3)3CH
B. C6H6
C. C8H18
D. Si(CH3)4
[1]
Markscheme
D
Examiners report
47% of the candidates identified TMS as the substance producing the strongest signal in a 1H NMR spectrum. The wording of this question was not ideal and several teachers commented on this. We do not usually refer to the strength but the area under the signal.
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).