Chemistry

For the reaction of lead and lead (IV) oxide with sulfuric acid in a car battery, the oxidation states of the participating atoms are

From this it can be seen that the elemental lead is oxidized to lead sulfate, while the Pb atom in the oxide is reduced to the 2 state in lead sulfate it follows then that elemental lead is the reducing agent, as it causes the lead oxide to be oxidized, while the lead oxide is the oxidizing agent.

    For the second reaction, it is clear from the charge of the iron (II) ion in the product side that elemental iron is being oxidized to its 2 state while the copper (II) ion is reduced to its elemental form. Following the same logic as in the previous problem, elemental iron is the reducing agent while the copper (II) ion is the oxidizing agent. If the elemental iron is kept in electric contact with the copper (II) ion solution, then over time the iron should be lost as iron (II) ion into the solution while the elemental copper deposits on the surface of the iron sample. In this system, elemental iron, the reducing agent, provides the electrons necessary to drive the reaction. These electrons go to the copper (II) ion, the oxidizing agent, to reduce it to its elemental state.