DP Chemistry (first assessment 2025)

Test builder »

Question 22M.1A.SL.TZ1.3

Date	May 2022	Marks available	[Maximum mark: 1]	Reference code	22M.1A.SL.TZ1.3
Level	SL	Paper	1A	Time zone	TZ1
Command term	Determine	Question number	3	Adapted from	N/A

3.

[Maximum mark: 1]

22M.1A.SL.TZ1.3

What is the molecular formula of a compound with an empirical formula of CHO₂ and a relative molecular mass of 90?

A. CHO₂

B. C₂H₂O₄

C. C₃H₆O₃

D. C₄H₁₀O₂

[1]

Markscheme

B

Syllabus sections

Structure 1. Models of the particulate nature of matter » Structure 1.4—Counting particles by mass: The mole » Structure 1.4.4—The empirical formula of a compound gives the simplest ratio of atoms of each element present in that compound. The molecular formula gives the actual number of atoms of each element present in a molecule. Interconvert the percentage composition by mass and the empirical formula. Determine the molecular formula of a compound from its empirical formula and molar mass.