DP Chemistry (first assessment 2025)
Question 22N.1A.SL.TZ0.6
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.SL.TZ0.6 |
| Level | SL | Paper | 1A | Time zone | TZ0 |
| Command term | Solve | Question number | 6 | Adapted from | N/A |
6.
[Maximum mark: 1]
22N.1A.SL.TZ0.6
What is the relative atomic mass of a sample of chlorine containing 70 % of the 35Cl isotope and 30 % of the 37Cl isotope?
A. 35.4
B. 35.5
C. 35.6
D. 35.7
[1]
Markscheme
C
Examiners report
73% of the candidates were able to calculate the relative atomic mass of the sample of chlorine correctly (which was 35.6) given the masses and percentage abundances of the isotopes without the use of a calculator.
Syllabus sections
Structure 3. Classification of matter » Structure 3.1—The periodic table: Classification of elements » Structure 3.1.8—Transition elements have incomplete d-sublevels that give them characteristic properties. Recognize properties, including: variable oxidation state, high melting points, magnetic properties, catalytic properties, formation of coloured compounds and formation of complex ions with ligands.
Structure 1. Models of the particulate nature of matter » Structure 1.2—The nuclear atom » Structure 1.2.2—Isotopes. Isotopes are atoms of the same element with different numbers of neutrons. Perform calculations involving non-integer relative atomic masses and abundance of isotopes from given data.