CAPE Chemistry Unit 1 · 2017 · Paper 1 · Question 12

Item 12 refers to the following redox reactions involving chromium compounds: Cr₂O₃ (NaOH, and water) → Na₂CrO₄ (dilute H₂SO₄) → Cr₂O₇²⁻. A table is provided showing oxidation numbers for Cr₂O₃, Na₂CrO₄, and Cr₂O₇²⁻.

What is the oxidation number of chromium in EACH compound?

This question uses a figure or table from the paper — you'll see it when you practise.