DP Chemistry (first assessment 2025)
Question 22N.1A.SL.TZ0.1
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.SL.TZ0.1 |
| Level | SL | Paper | 1A | Time zone | TZ0 |
| Command term | Solve | Question number | 1 | Adapted from | N/A |
1.
[Maximum mark: 1]
22N.1A.SL.TZ0.1
How many oxygen atoms are present in 0.0500 mol Ba(OH)2•8H2O?
NA = 6.02 × 1023
A. 3.01 × 1023
B. 6.02 × 1023
C. 3.01 × 1024
D. 6.02 × 1024
[1]
Markscheme
A
Examiners report
57% of the candidates calculated the number of oxygen atoms correctly. The most commonly chosen distractor was C which would be achieved if a power of ten error was made.
Syllabus sections
Structure 1. Models of the particulate nature of matter » Structure 1.4—Counting particles by mass: The mole » Structure 1.4.1—The mole (mol) is the SI unit of amount of substance. One mole contains exactly the number of elementary entities given by the Avogadro constant. Convert the amount of substance, n, to the number of specified elementary entities.