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The overall reactions of a hydrogen -oxy...

The overall reactions of a hydrogen -oxygen fuel cell is

A

`2H_(2(g)) + O_(2(g)) to 2H_2O_((l))`

B

`2H_(2(g)) + 4OH_((aq)) to 4H_2O_((l)) + 4e^(-)`

C

`O_(2(g)) + 2H_2O_((l)) + 4e^(-) to 4OH_((aq))^-`

D

`4OH_((aq))^(-) + 4e^(-) to 2H_2O_((l))`

Text Solution

Verified by Experts

The correct Answer is:
A
`{:("At anode:",2H_(2(g))+4OH_((aq))^(-) to 4H_2O_((l))+4e^(-)),("At cathode:",O_(2(g))+2H_2O_((l))+4e^(-) to 4OH_((aq))),("Overall reaction:",2H_(2(g)) +O_(2(g)) to 2H_2O_((l))):}`
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Fuel Cells

The middle compartment of the hydrogen-oxygen fuel cell contains, hot aqueous solution of _________.

Knowledge Check

  • A fuel cell is

    A
    the voltaic cells in which discontinuous supply of fuels are send at anode to give oxidation
    B
    the voltaic cell in which fuels such as : `CH_(4) , H_(2) , CO` are used up at anode
    C
    it involves the reactions of `H_(2) - O_(2)` fuel cell such as
    Cathode : `2 H_(2) + 4OH^(-) to 4 H_(2) O(l) + 4e`
    Anode : `O_(2) + 2 H_(2)O (l) + 4e to 4 OH^(-)`
    D
    the efficiency of a `H_(2) - O_(2)` fuel cell is very low

  • Purpose of hydrogen -oxygen fuel cell is to

    A
    Generate heat
    B
    Ccreate potential difference
    C
    Produce high purity water
    D
    Remove adsorbed oxygen from electrode surface

  • The effciency of the hydrogen-oxygen fuel cell is about

    A
    0.2
    B
    0.4
    C
    0.7
    D
    0.9

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    Fuel cells : Fuel cells are galvanic cells in which the chemical energy of fuel cell is directly converted into electrical energy. A type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst ( platinum, silver, or metal oxide ). The electrodes are placed in aqueous solution of NaOH . Oxygen and hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(o+) which is neutralized by overset(c-)(O)H, i.e., anodic reaction. At cathode, O_(2) gets reduced to overset(c-)(O)H Hence, the net reaction is The overall reaction has DeltaH=-285.6 kJ mol^(-1) and DeltaG=-237.4 kJ mol^(-1) at 25^(@)C If the cell voltage is 1.23V for the H_(2)-O_(2) fuel cell and for the half cell :

    Fuel cells : Fuel cells are galvanic cells in which the chemical energy of fuel cell is directly converted into electrical energy. A type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst ( platinum, silver, or metal oxide ). The electrodes are placed in aqueous solution of NaOH . Oxygen and hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(o+) which is neutralized by overset(c-)(O)H, i.e., anodic reaction. At cathode, O_(2) gets reduced to overset(c-)(O)H Hence, the net reaction is The overall reaction has DeltaH=-285.6 kJ mol^(-1) and DeltaG=-237.4 kJ mol^(-1) at 25^(@)C What is the value of DeltaS^(c-) for the fuel cell at 25^(@)C ?

    Fuel cells : Fuel cells are galvanic cells in which the chemical energy of fuel cell is directly converted into electrical energy. A type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst ( platinum, silver, or metal oxide ). The electrodes are placed in aqueous solution of NaOH . Oxygen and hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(o+) which is neutralized by overset(c-)(O)H, i.e., anodic reaction. At cathode, O_(2) gets reduced to overset(c-)(O)H Hence, the net reaction is The overall reaction has DeltaH=-285.6 kJ mol^(-1) and DeltaG=-237.4 kJ mol^(-1) at 25^(@)C Suppose the concentration of hydroxide ioin in the cell is doubled, then the cell voltage will be

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    Which of the following is NOT used in hydrogen-oxygen fuel cell ?

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