Which equation shows the reaction at the cathode in an acidic hydrogen-oxygen fuel cell?
H2(g)→2H+(aq)+2e−\text{H}_2\text{(g)} \rightarrow 2\text{H}^+\text{(aq)} + 2\text{e}^-H2(g)→2H+(aq)+2e−
O2(g)+4H+(aq)+4e−→2H2O(l)\text{O}_2\text{(g)} + 4\text{H}^+\text{(aq)} + 4\text{e}^- \rightarrow 2\text{H}_2\text{O(l)}O2(g)+4H+(aq)+4e−→2H2O(l)
2H2(g)+O2(g)→2H2O(l)2\text{H}_2\text{(g)} + \text{O}_2\text{(g)} \rightarrow 2\text{H}_2\text{O(l)}2H2(g)+O2(g)→2H2O(l)
O2(g)+2H2O(l)+4e−→4OH−(aq)\text{O}_2\text{(g)} + 2\text{H}_2\text{O(l)} + 4\text{e}^- \rightarrow 4\text{OH}^-\text{(aq)}O2(g)+2H2O(l)+4e−→4OH−(aq)