Identify the species that is being oxidized in the following balanced reaction.
3 Pb²+ (aq) + 2 Cr (s) → 3 Pb (s) + 2 Cr³⁺ (aq)

• A. Pb²⁺
• B. Cr³⁺
• C. Pb
• D. Cr

Answer: (D)

Verified step by step guidance

1. Identify the oxidation states of each element in the reactants and products. For Pb2+ (aq), the oxidation state is +2. For Cr (s), the oxidation state is 0. For Pb (s), the oxidation state is 0. For Cr3+ (aq), the oxidation state is +3.
2. Determine the change in oxidation states for each element. Pb2+ changes from +2 to 0, indicating a reduction. Cr changes from 0 to +3, indicating an oxidation.
3. Recognize that oxidation involves an increase in oxidation state, while reduction involves a decrease in oxidation state.
4. Identify the species that undergoes an increase in oxidation state. In this reaction, Cr goes from an oxidation state of 0 to +3.
5. Conclude that the species being oxidized is Cr, as it experiences an increase in oxidation state from 0 to +3.