Question

The overall reaction of a hydrogen-oxygen fuel cell is

• A. $2H_{2\left(g\right)}+O_{2\left(g\right)} \to2H_{2}O_{\left(l\right)}$
• B. $2H_{2\left(g\right)}+4OH^{-}_{\left(aq\right)} \to4H_{2}O_{\left(l\right)}+4e^{-}$
• C. $O_{2\left(g\right)}+2H_{2}O_{\left(l\right)}+4e^{-} \to4OH^{-}_{\left(aq\right)}$
• D. $4OH^{-}_{\left(aq\right)}+4e^{-} \to2H_{2}O_{\left(l\right)}$

Answer 1

Answer: (A)

At anode : $2H_{2\left(g\right)}+4OH^{-}_{\left(aq\right)} \to4H_{2}O_{\left(l\right)}+4e^{-}$
At cathode : $O_{2\left(g\right)}+2H_{2}O_{\left(l\right)}+4e^{-} \to4OH_{\left(aq\right)}$
Overall reaction : $2H_{2\left(g\right)}+O_{2\left(g\right)} \to2H_{2}O_{\left(l\right)}$