Chapter 19, Problem 19.33P

Another method of hydrogen production is the electrolysis of water (Section 19.12). If the electricity is generated from a clean energy source such as solar energy instead of fossil fuels, then hydrogen production could he less polluting.
Anode (oxidation): ${\text{2H}}_{\text{2}}\text{O(l)}\to {\text{O}}_{\text{2}}(g)+4H^{+}(aq)+4e^{-}$
Cathode (reduction): $\begin{array}{l}4H_{2}O(l)+4e^{-}\to \\ {\text{ 2H}}_{\text{2}}(g)+4{\text{OH}}^{\text{-}}(aq)\end{array}$
Overall cell reaction: $\begin{array}{l}6H_{2}O(l)\to \\ {\text{ 2H}}_{\text{2}}(g)+{\text{O}}_{\text{2}}{\text{(aq)+4H}}^{\text{+}}(aq)+4{\text{OH}}^{\text{-}}(aq)\end{array}$
(a) How many grams of H₂(g) will be produced if 250.0 A is applied for 30.0 minutes?
(b) How long will it take to produce 25.0 mol of 0₂ using a curr ent of 500.0 A?