Question 22M.2.sl.TZ2.4a(i)
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.2.sl.TZ2.4a(i) |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Outline | Question number | a(i) | Adapted from | N/A |
Carbon forms many compounds.
C60 and diamond are allotropes of carbon.
Outline one difference between the bonding of carbon atoms in C60 and diamond.
[1]
C60 fullerene: «each carbon is» bonded to 3 C AND diamond: bonded to 4 C
OR
C60 fullerene: delocalized/resonance AND diamond: not delocalized/no resonance
OR
C60 fullerene: single and double bonds AND diamond: single bonds ✔
Accept “C60 fullerene: sp2 AND diamond: sp3”.
Accept “C60 fullerene: trigonal planar geometry / bond angles between 109.5°/109°/108°–120° AND diamond: tetrahedral geometry / bond angle 109.5°/109°”.
Accept "bonds in fullerene are shorter/stronger/have higher bond order".
This was a challenging question that asked about the difference between the bonding of carbon atoms in C60 and diamond. 20% of the candidates gained the mark. The majority of the candidates did not have a specific enough answer for C60 and mentioned the pentagons and hexagons but not the number of bonds or the geometry or the bond order or the electron delocalisation. Diamond was better known to candidates as expected.
