Redox Reactions And Electrochemistry Ques 48
Question: In a hydrogen - oxygen fuel cell, combustion of hydrogen occurs to [AIEEE 2004]
Options:
A) Produce high purity water
B) Create potential difference between the two electrodes
C) Generate heat
D) Remove adsorbed oxygen from electrode surfaces
Show Answer
Answer:
Correct Answer: B
Solution:
In hydrogen-oxygen fuel cell following reactions take place to create potential difference between two electrodes.
$ 2H_2{(g)}+4O{H^{-}} _{(aq)}\to 4H_2{O _{(l)}}+4{e^{-}} $
$ O_2{(g)}+2H_2{O _{(l)}}+4{e^{-}}\to 4O{H^{-}} _{(aq)} $
Overall reaction = $ 2H_2{(g)}+{O _{2(g)}}\to 2H_2{O _{(l)}} $
the net reaction is the same as burning (Combustion) of hydrogen to form water.