DP Chemistry (last assessment 2024)
Question 22N.1.hl.TZ0.30
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1.hl.TZ0.30 |
| Level | hl | Paper | 1 | Time zone | TZ0 |
| Command term | Solve | Question number | 30 | Adapted from | N/A |
30.
[Maximum mark: 1]
22N.1.hl.TZ0.30
The standard electrode potentials for three half-cells involving chromium are shown.
Cr3+ (aq) + e− Cr2+ (aq) E⦵ = −0.407 V
Cr3+ (aq) + 3e− Cr (s) E⦵ = −0.744 V
Cr2+ (aq) + 2e− Cr (s) E⦵ = −0.914 V
Which statement is correct?
A. Cr3+ (aq) can oxidize Cr2+ (aq) but not Cr (s).
B. Cr3+ (aq) can oxidize Cr (s) but not Cr2+ (aq).
C. Cr3+ (aq) can oxidize both Cr2+ (aq) and Cr (s).
D. Cr3+ (aq) can oxidize Cr (s) and reduce Cr2+ (aq).
[1]
Markscheme
B
Examiners report
A poorly answered question with only 33% of candidates being able to deduce the relative strengths of oxidizing and reducing agents based on standard electrode potential data. All distractors were quite effective, indicating significant confusion.