In a fuel cell `H_(2)` and `O_(2)` react to produce electricity. In the process `H_(2)` gas is oxidised at the anode and `O_(2)` is reduced at the cathode. If 6.72 litre of `H_(2)` at NTP reacts in 15 minute, what is the average current produced ? If the entire current is used for electro-deposition of Cu from `Cu^(2+)`, how many g of Cu are deposited ?

Explanation

React at anode of fuel cell,
`{:(H_(2) (g),rarr,2H^(+),+,2e^(-)),(1 " mole",,,,"2 mole "),(22.4 L,,,,2F):}`
67.2 L of `H_(2)` correspond `= (2 xx 96500)/(22.4) xx 67.2` coulomb
Time `= 15 xx 60` second
Average current `= (2xx 96500 xx 67.2)/(22.4 xx 15 xx 60) = 643.3 amp`
Mass of copper deposited by `(2 xx 96500)/(22.4) xx 67.2` coulomb
`= (63.5)/(2 xx 96500) xx (2 xx 96500 xx 67.2)/(22.4)`
`= 190.5 g`