DP Chemistry (last assessment 2024)
Question 19N.2.hl.TZ0.1b
Date | November 2019 | Marks available | [Maximum mark: 2] | Reference code | 19N.2.hl.TZ0.1b |
Level | hl | Paper | 2 | Time zone | TZ0 |
Command term | Outline, Predict | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19N.2.hl.TZ0.1b
The equations show steps in the formation and decomposition of ozone in the stratosphere, some of which absorb ultraviolet light.
Step 1 O2 → 2O•
Step 2 O• + O2 → O3
Step 3 O3 → O• + O2
Step 4 O• + O3 → 2O2
(b)
Outline why both bonds in the ozone molecule are the same length and predict the bond length in the ozone molecule. Refer to section 10 of the data booklet.
Reason:
Length:
[2]
Markscheme
resonance «structures»
OR
delocalization of «the double/pi bond» electrons ✔
121 «pm» < length < 148 «pm» ✔
NOTE: Accept any length between these two values.
