DP Chemistry (first assessment 2025)
Question 22N.1A.HL.TZ0.10
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.HL.TZ0.10 |
| Level | HL | Paper | 1A | Time zone | TZ0 |
| Command term | Identify | Question number | 10 | Adapted from | N/A |
10.
[Maximum mark: 1]
22N.1A.HL.TZ0.10
Which elements are capable of forming expanded octets?
I. Nitrogen
II. Phosphorus
III. Arsenic
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
[1]
Markscheme
C
Examiners report
Only about 60% of candidates were aware that nitrogen cannot expand its octet, unlike other elements in Group 15. There were quite a lot of teacher comments mainly regarding the inclusion of arsenic, but the critical factor did not require any knowledge of this.
Syllabus sections
Structure 2. Models of bonding and structure » Structure 2.2—The covalent model » Structure 2.2.13—Some atoms can form molecules in which they have an expanded octet of electrons. Visually represent Lewis formulas for species with five and six electron domains around the central atom. Deduce the electron domain geometry and the molecular geometry for these species using the VSEPR model.