Final answer:
Redox processes involve the transfer of electrons, with oxidation being the loss of electrons and reduction being the gain. In the given options, B (VO₃ → VO₂), D (NO₂⁻ → NO₃⁻), and E (Cr³⁻ → CrO₄²⁻) are redox processes, as they involve changes in oxidation states of the elements involved.
Step-by-step explanation:
The question asks to identify which of the following are redox processes:
- A. CO₂ → CO₃²⁻
- B. VO₃ → VO₂
- C. SO₃ → SO₄²⁻
- D. NO₂⁻ → NO₃⁻
- E. Cr³⁻ → CrO₄²⁻
A redox process involves the transfer of electrons between two species. Oxidation refers to the loss of electrons, while reduction is the gain of electrons. To identify if a process is redox, we need to look at the oxidation states of the atoms before and after the reaction. If there is a change in oxidation state, then the process is redox.
For example:
- B. VO₃ → VO₂: Vanadium is reduced as it goes from an oxidation state of +5 in VO₃ to +4 in VO₂.
- D. NO₂⁻ → NO₃⁻: Nitrogen is oxidized as it goes from an oxidation state of +3 in NO₂⁻ to +5 in NO₃⁻.
- E. Cr³⁻ → CrO₄²⁻: Chromium is oxidized as it goes from an oxidation state of +3 in Cr³⁻ to +6 in CrO₄²⁻.
Therefore, the processes B, D, and E are redox processes.