DP Chemistry (last assessment 2024)
Question 22N.1.sl.TZ0.4
Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1.sl.TZ0.4 |
Level | sl | Paper | 1 | Time zone | TZ0 |
Command term | Identify | Question number | 4 | Adapted from | N/A |
4.
[Maximum mark: 1]
22N.1.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.