Chemistry - Electrochemistry Question with Solution | TestHub

ChemistryElectrochemistryGalvanic cells/Nernst Equation/Concentration CellsHard2 minPYQ_2020
ChemistryHardnumerical

Consider a 70% efficient hydrogen-oxygen fuel cell working under standard conditions at 1 bar and 298 K. Its cell reaction is

H2(g)+12O2(g)H2O(l)

The work derived from the cell on the consumption of 1.0×10-3 mol of H2(g) is used to compress 1.00 mol of a monoatomic ideal gas in a thermally insulated container. What is the change in the temperature (in K ) of the ideal gas?

The standard reduction potentials for the two half-cells are given below.

O2(g)+4H+(aq)+4e-2H2O(l),  E0=1.23 V,

2H+(aq)+2e-H2(g),  E0=0.00 V

Use F=96500 C mol-1,R=8.314 J mol-1K-1.

 

Answer:
13.32
Solution:

For given reaction H2g+12O2g2e-H2Ol  E°=1.23 V

ΔG°=-nFEcell °=[-2×96500×1.23] 1×10-3×0.7=-166.173 J

W=166.173 J

W=nRΔTγ-1

166.173=1×8.314×ΔT53-1=8.314×32ΔT

ΔT=166.173×28.314×3=13.32

Stream:JEE_ADVSubject:ChemistryTopic:ElectrochemistrySubtopic:Galvanic cells/Nernst Equation/Concentration Cells
2mℹ️ Source: PYQ_2020

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