To understand which substances are being oxidized and reduced in the given chemical reaction, iron oxide + carbon -> iron + carbon monoxide, we need to analyze the changes in oxidation states of the elements involved.
1. Identify the reactants and products:
- Reactants: Iron oxide (Fe₂O₃) and carbon (C)
- Products: Iron (Fe) and carbon monoxide (CO)
2. Determine the oxidation states:
- For iron oxide (Fe₂O₃), each iron (Fe) has an oxidation state of +3, and each oxygen (O) has an oxidation state of -2.
- For elemental carbon (C), the oxidation state is 0.
- In the product iron (Fe), the oxidation state of iron is 0.
- In carbon monoxide (CO), the oxidation state of carbon (C) is +2 and oxygen is -2.
3. Identify the changes in oxidation states:
- Iron (Fe) changes from +3 in Fe₂O₃ to 0 in Fe.
- Carbon (C) changes from 0 in elemental carbon to +2 in CO.
4. Determine what is being oxidized and reduced:
- Oxidation involves an increase in oxidation state. Carbon's oxidation state increases from 0 to +2, meaning carbon is being oxidized.
- Reduction involves a decrease in oxidation state. Iron's oxidation state decreases from +3 to 0, meaning iron is being reduced.
Based on this analysis, the correct answer is:
B. carbon, iron
