1)

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


A) Produce high purity water

B) Create potential difference between the two electrodes

C) Generate heat

D) Remove adsorbed oxygen from electrode surfaces

Answer:

Option B

Explanation:

In a hydrogen-oxygen fuel cell, following reactions take place to create a potential difference between the two electrodes.

$2H_{2} (g) + 4OH^{-}(aq) \rightarrow 4H2O (l) + 4e^{-}$

$O_{2} (g) + 2H_{2}O(l) + 4e^{-} \rightarrow 4OH^{-}(aq)$

$Overall reaction = 2H_{2} (g) + O_{2} (g) \rightarrow 2H_{2}O(l)$

the net reaction is the same as burning (combustion) of hydrogen to form water.