DP Chemistry (first assessment 2025)

Test builder »

Question 21M.1A.HL.TZ2.28

Date	May 2021	Marks available	[Maximum mark: 1]	Reference code	21M.1A.HL.TZ2.28
Level	HL	Paper	1A	Time zone	TZ2
Command term	Determine	Question number	28	Adapted from	N/A

28.

[Maximum mark: 1]

21M.1A.HL.TZ2.28

Which spectra would show the difference between propan-2-ol, CH₃CH(OH)CH₃, and propanal, CH₃CH₂CHO?

I. mass
II. infrared
III. ¹H NMR

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

[1]

Markscheme

D

Syllabus sections

Structure 3. Classification of matter » Structure 3.2—Functional groups: Classification of organic compounds » Structure 3.2.8—Mass spectrometry (MS) of organic compounds can cause fragmentation of molecules. Deduce information about the structural features of a compound from specific MS fragmentation patterns.

Structure 3. Classification of matter » Structure 3.2—Functional groups: Classification of organic compounds » Structure 3.2.9—Infrared (IR) spectra can be used to identify the type of bond present in a molecule. Interpret the functional group region of an IR spectrum, using a table of characteristic frequencies (wavenumber/cm–1).

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).