JEE Main · 2004 · 24 Apr 2004 · Offline · Redox Reactions and Electrochemistry

In hydrogen - oxygen fuel cell, combustion of hydrogen occurs to

(A)generate heat
(B)remove adsorbed oxygen from electrode surfaces
(C)produce high purity water
(D)create potential difference between the two electrodes✓ Correct

Answer: (D)

Solution

In a hydrogen-oxygen fuel cell the hydrogen is oxidised at one electrode and oxygen reduced at the other, and these two half-reactions set up a potential difference between the electrodes. That potential difference is what drives electrons round the external circuit to deliver electrical energy. Water and some heat come out as by-products, but the point of oxidising the hydrogen is to create the cell voltage.

JEE Main · 2004 · 24 Apr 2004 · Offline · Single correct option

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