DP Chemistry (first assessment 2025)

Test builder »

Question 21N.1A.SL.TZ0.12

Date	November 2021	Marks available	[Maximum mark: 1]	Reference code	21N.1A.SL.TZ0.12
Level	SL	Paper	1A	Time zone	TZ0
Command term	Determine	Question number	12	Adapted from	N/A

12.

[Maximum mark: 1]

21N.1A.SL.TZ0.12

The following compounds have similar relative molecular masses. What is the order of increasing boiling point?

A. CH₃CH₂CH₂OH < CH₃CH₂CHO < CH₃COOH

B. CH₃CH₂CHO < CH₃CH₂CH₂OH < CH₃COOH

C. CH₃CH₂CHO < CH₃COOH < CH₃CH₂CH₂OH

D. CH₃COOH < CH₃CH₂CHO < CH₃CH₂CH₂OH

[1]

Markscheme

B

Syllabus sections

Structure 2. Models of bonding and structure » Structure 2.2—The covalent model » Structure 2.2.9—Given comparable molar mass, the relative strengths of intermolecular forces are generally: London (dispersion) forces < dipole–dipole forces < hydrogen bonding. Explain the physical properties of covalent substances to include volatility, electrical conductivity and solubility in terms of their structure.