DP Chemistry (first assessment 2025)

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Question 19M.2.HL.TZ1.14

Date	May 2019	Marks available	[Maximum mark: 2]	Reference code	19M.2.HL.TZ1.14
Level	HL	Paper	2	Time zone	TZ1
Command term	Identify, Name	Question number	14	Adapted from	N/A

14.

[Maximum mark: 2]

19M.2.HL.TZ1.14

Aspirin can be obtained from salicylic acid.

Unreacted salicylic acid may be present as an impurity in aspirin and can be detected in the infrared (IR) spectrum.

Name the functional group and identify the absorption band that differentiates salicylic acid from aspirin. Use section 26 of the data booklet.

Name:

Absorption band:

[2]

Markscheme

Name:
hydroxyl [✔]

Absorption band:
3200–3600 «cm^–1» [✔]

Note: Accept “phenol” OR “alcohol” but not “hydroxide”.

Examiners report

Many students could correctly identify a difference between the given structures and state a region in the IR spectrum where this would absorb.

Syllabus sections

Structure 3. Classification of matter » Structure 3.2—Functional groups: Classification of organic compounds » Structure 3.2.2—Functional groups give characteristic physical and chemical properties to a compound. Organic compounds are divided into classes according to the functional groups present in their molecules. Identify the following functional groups by name and structure: halogeno, hydroxyl, carbonyl, carboxyl, alkoxy, amino, amido, ester, phenyl.

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).