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| Numerical 04 |
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| 04. A steady current of 10.0 A is passed through a water voltameter for 300s. Estimate the volume of H2 evolved at standard temperature and pressure. Use the known value of Faraday's constant. Relative molecular mass of H2 is 2.016 and molar volume = 22.4 litres (volume of 1m of an ideal gas at STP). |
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| Suggested solution: |
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| Current, I = 10.0 A; t=300 s |
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| Charge = It = 3000 C = 3 x 103 C |
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| Since, H2 is diatomic, |
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| We know from the definition of Faraday's constant that 9650o C of charge is required to liberate 1.008 g of hydrogen. |
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| \ Charge required to liberate one molar mass of hydrogen at STP |
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| Since one molar mass of hydrogen at STP occupies a volume of 22.4 litres. |
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| \ Volume of hydrogen evolved on passing 3 x 103 C of charge. |
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