Review problem 5.040 for each reaction, identify in order the substance oxidized, the substance reduced, the oxidizing agent, and the reducing agent. (a) cu + 2h2so4 → cuso4 + so2 +2h2o h2so4; cu; cu; h2so4 cu; h2so4; cu; h2so4 cu; h2o; h2o; cu h2so4; cu; h2so4; cu cu; h2so4; h2so4; cu (b) 3so2 + 2hno3 + 2h2o → 3h2so4 + 2no hno3; so2; so2; hno3 so2; h2o; h2o; so2 so2; hno3; hno3; so2 hno3; so2; hno3; so2 so2; hno3; so2; hno3 (c) 5h2so4 + 4zn → 4znso4 + h2s +4h2o h2so4; zn; h2so4; zn zn; h2so4; zn; h2so4 h2so4; zn; zn; h2so4 zn; h2o; h2o; zn zn; h2so4; h2so4; zn (d) i2 + 10hno3 → 2hio3 + 10no2 + 4h2o i2; hno3; hno3; i2 hno3; i2; hno3; i2 hno3; i2; i2; hno3 i2; hno3; h2o; i2 i2; hno3; i2; hno3

A. The correct option is: Cu; H₂SO₄; H₂SO₄; Cu

B. The correct option is: SO₂; HNO₃; HNO₃; SO₂

C. The correct option is: Zn; H₂SO₄; H₂SO₄; Zn

D. The correct option is: I₂; HNO₃; HNO₃; I₂

Explanation:

A chemical reaction that involves the simultaneous transfer of electrons between two chemical species is known as the redox reaction.

In this reaction, a species that gains electrons, thus getting reduced is called the oxidizing agent. Whereas, species that loses electrons, thus getting oxidized is called the reducing agent.

Oxidation refers to an increase in the oxidation state and reduction refers to a decrease in the oxidation state.

A. Cu + 2H₂SO₄ → CuSO₄ + SO₂ +2H₂O

In this reaction, Cu goes from 0 in Cu to +4 oxidation state in CuSO₄ and thus gets oxidized. Whereas, S goes from +6 in H₂SO₄ to +4 oxidation state in SO₂ and thus gets reduced. Therefore, H₂SO₄ is the oxidizing agent and Cu is the reducing agent.

The correct option is: Cu; H₂SO₄; H₂SO₄; Cu

B. 3SO₂ + 2HNO₃ + 2H₂O → 3H₂SO₄ + 2NO

In this reaction, S goes from +4 in SO₂ to +6 oxidation state in H₂SO₄ and thus gets oxidized. Whereas, N goes from +5 in HNO₃ to +2 oxidation state in NO and thus gets reduced. Therefore, HNO₃ is the oxidizing agent and SO₂ is the reducing agent.

The correct option is: SO₂; HNO₃; HNO₃; SO₂

C. 5H₂SO₄ + 4Zn → 4ZnSO₄ + H₂S +4H₂O

In this reaction, Zn goes from 0 in Cu to +2 oxidation state in ZnSO₄ and thus gets oxidized. Whereas, S goes from +6 in H₂SO₄ to -2 oxidation state in H₂S and thus gets reduced. Therefore, H₂SO₄ is the oxidizing agent and Zn is the reducing agent.

The correct option is: Zn; H₂SO₄; H₂SO₄; Zn

D. I₂ + 10HNO₃ → 2HIO₃ + 10NO₂ + 4H₂O

In this reaction, I goes from 0 in I₂ to +5 oxidation state in HIO₃ and thus gets oxidized. Whereas, N goes from +5 in HNO₃ to +4 oxidation state in NO₂ and thus gets reduced. Therefore, HNO₃ is the oxidizing agent and I₂ is the reducing agent.  

The correct option is: I₂; HNO₃; HNO₃; I₂