DP Chemistry (first assessment 2025)

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Question 22N.1A.SL.TZ0.4

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Date November 2022 Marks available [Maximum mark: 1] Reference code 22N.1A.SL.TZ0.4
Level SL Paper 1A Time zone TZ0
Command term Identify Question number 4 Adapted from N/A
4.
[Maximum mark: 1]
22N.1A.SL.TZ0.4

Which is a possible empirical formula for a substance with Mr = 42?


A.  CH

B.  CH2

C.  C3H6

D.  C3H8

[1]

Markscheme

B

Examiners report

This question needed careful reading. The majority of candidates chose distractor C (C3H6) which had an Mr of 42. But what the question asked for was the empirical formula of the compound. Only 40% of the candidates chose the correct answer (CH2). The question discriminated well between high-scoring and low-scoring candidates. However, it was the only question on this paper for which the correct answer was not the most commonly chosen answer.

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