Final answer:
In the three-step production of sulfuric acid, step 1 and step 2 are redox reactions, while step 3 is not a redox reaction.
Step-by-step explanation:
In the three-step production of sulfuric acid, we need to assign oxidation numbers to each substance to determine which reactions are redox and which are not:
Step 1: [S + O₂ → SO₂]
Step 2: [SO₂ + O₂ → SO₃]
Step 3: [SO₃ + H₂O → H₂SO₄]
Let's assign oxidation numbers to the elements involved:
In step 1, sulfur (S) has an oxidation number of 0 and oxygen (O) has an oxidation number of -2 in SO₂. Since there is a change in the oxidation number of sulfur from 0 to +4, this reaction is a redox reaction.
In step 2, sulfur dioxide (SO₂) and oxygen (O₂) combine to form sulfur trioxide (SO₃). In SO₂, sulfur has an oxidation number of +4 and oxygen has an oxidation number of -2, while in SO₃, sulfur has an oxidation number of +6 and oxygen has an oxidation number of -2. Since there is a change in oxidation numbers for both elements, this reaction is also a redox reaction.
In step 3, sulfur trioxide (SO₃) reacts with water (H₂O) to form sulfuric acid (H₂SO₄). In SO₃, sulfur has an oxidation number of +6, while in H₂SO₄, sulfur has an oxidation number of +6. Since there is no change in the oxidation number of sulfur in this step, this reaction is not a redox reaction.
Therefore, the correct answer is: a) Step 1: Redox, Step 2: Redox, Step 3: Not Redox.