Lead-acid batteries, which are used in cars, consist of several rechargeable cells connected in series, and they were first developed in $1860$. One drawback is that they have a fairly large mass for the amount of energy stored. When these batteries discharge, the electrode reactions in the cells are as follows: I $\ \text{Pb} + \text{SO}_4^{2-} \rightarrow \text{PbSO}_4 + 2\text{e}^-$ II $\ \text{PbO}_2 + 4\text{H}^+ + \text{SO}_4^{2-} + 2\text{e}^- \rightarrow \text{PbSO}_4 + 2\text{H}_2\text{O}$ State which of these reactions occurs at the positive electrode in a lead-acid cell during discharge, and explain your answer.
Using the Data Booklet and equations I and II above, calculate the voltage produced by a lead-acid cell under standard conditions.
In one reaction that occurs in nickel-metal hydride batteries, $\text{NiO(OH)} + \text{H}_2\text{O} + \text{e}^- \rightleftharpoons \text{Ni(OH)}_2 + \text{OH}^-$. State the oxidation state of nickel in $\text{NiO(OH)}$.
Suggest one probable advantage of these batteries compared with lead-acid batteries.
Hydrogen fuel cells have been proposed as the next major development in electrically powered vehicles. In these fuel cells, hydrogen is oxidized to form water, using a catalyst and inert electrodes. Suggest a material for the electrodes.
Use your knowledge of hydrogen to suggest one disadvantage of these fuel cells for powering vehicles.
Many countries around the world are developing methods of recycling materials that are valuable or that need large amounts of energy to produce. For each recyclable material below, state whether recycling it is important for saving energy or for saving resources. Use your chemistry knowledge to explain each decision. glass steel plastics