DP Chemistry (first assessment 2025)
Question 19M.1A.HL.TZ2.11
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.HL.TZ2.11 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 11 | Adapted from | N/A |
11.
[Maximum mark: 1]
19M.1A.HL.TZ2.11
Which species has a square planar molecular geometry?
A. SF4
B. XeF4
C. CF4
D. PF4+
[1]
Markscheme
B
Examiners report
This was a highly discriminating question. 67 % of the candidates identified the species that has a square planar molecular geometry. One teacher commented that this was a difficult recall question. However, the intention here is not to memorize shapes but rather to use VSEPR theory to deduce the shape.
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.