Q.Explain the function of the $\text{H}_2\text{-O}_2$ fuel cell.

Step 1. In the hydrogen-oxygen fuel cell, hydrogen gas is continuously supplied as fuel to a porous anode and oxygen gas as oxidant to a porous cathode, both made of nickel/nickel-oxide-impregnated graphite, with aqueous KOH as the electrolyte (~200°C, 20-40 atm).

Step 2. At the anode, hydrogen is oxidised in the presence of hydroxide ions: $2\text{H}_2\text{(g)}+4\text{OH}^{-}\text{(aq)} \rightarrow 4\text{H}_2\text{O(l)}+4e^{-}$.

Step 3. At the cathode, oxygen is reduced, consuming water and regenerating hydroxide ions: $\text{O}_2\text{(g)}+2\text{H}_2\text{O(l)}+4e^{-} \rightarrow 4\text{OH}^{-}\text{(aq)}$. …

Describe the anode and cathode half-reactions, combine them into the overall reaction, and explain why keeping them physically sepa …

Describing the fuel cell as if hydrogen and oxygen react directly (like ordinary combustion) rather than explaining the separated hal …