DP Chemistry (first assessment 2025)
Question 19M.2.SL.TZ2.d(ii)
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.SL.TZ2.d(ii) |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | State | Question number | d(ii) | Adapted from | N/A |
d(ii).
[Maximum mark: 1]
19M.2.SL.TZ2.d(ii)
State, giving a reason, the shape of the dinitrogen monoxide molecule.
[1]
Markscheme
linear AND 2 electron domains
OR
linear AND 2 regions of electron density [✔]
Note: Accept “two bonds AND no lone pairs” for reason.
Examiners report
Though quite a number of candidates suggested a linear shape correctly, they often failed to give a complete correct explanation, just mentioning the absence of lone pairs but not two bonds, instead of referring to electron domains.
Syllabus sections
Structure 2. Models of bonding and structure » Structure 2.2—The covalent model » Structure 2.2.4—The valence shell electron pair repulsion (VSEPR) model enables the shapes of molecules to be predicted from the repulsion of electron domains around a central atom. Predict the electron domain geometry and the molecular geometry for species with up to four electron domains.