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InterviewSolution
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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` What is the value of `DeltaS^(c-)` for the fuel cell at `25^(@)C`?A. `-1600 J K^(-1)`B. `-160 J K^(-1)`C. `160 J K^(-1)`D. `1600 J K^(-1)` |
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Answer» Correct Answer - b `DeltaG^(c-)=DeltaH^(c-)-T DeltaS^(c-)` `implies-237.4=-285.6-298DeltaS^(c-)` `:. DeltaS^(c-)=-160J K^(-1)` |
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