Question 22M.2.hl.TZ1.a(ii)
| Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.hl.TZ1.a(ii) |
| Level | hl | Paper | 2 | Time zone | TZ1 |
| Command term | Deduce, Show | Question number | a(ii) | Adapted from | N/A |
Nitric acid is usually produced by the oxidation of ammonia.
Deduce a Lewis (electron dot) structure of the nitric acid molecule, HNO3, that obeys the octet rule, showing any non-zero formal charges on the atoms.
[2]
bonds and non-bonding pairs correct ✔
formal charges correct ✔
Accept dots, crosses or lines to represent electron pairs.
Do not accept resonance structures with delocalised bonds/electrons.
Accept + and – sign respectively.
Do not accept a bond between nitrogen and hydrogen.
For an incorrect Lewis structure, allow ECF for non-zero formal charges.
Drawing the Lewis structure of HNO3 was performed extremely poorly with structures that included H bonded to N, no double bond or a combination of single, double and even a triple bond or incorrect structures with dotted lines to reflect resonance. Many did not calculate non-zero formal charges.
