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Electrochemistry question

2009 · Q89
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Electrochemistry question

2009 · Q89

NEETChemistryElectrochemistryMCQ+4 / −1
Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 ×\times× 104 amperes of current is passed through molten Al2O3 for 6 hours, what mass of aluminium is product? (Assume 100% current efficiency, at mass of Al = 27 g mol−-−1).
  1. A
    8.1 ×\times× 104 g
  2. B
    2.4 ×\times× 105 g
  3. C
    1.3 ×\times× 104 g
  4. D
    9.0 ×\times× 103 g
View written solutionFree

Correct answer: A

E = Z × 96500

⇒\Rightarrow⇒ 273{{27} \over 3}327​ = Z ×\times× 96500

⇒\Rightarrow⇒ Z = 996500{9 \over {96500}}965009​

Now applying the formula, W = Z × I × t

W = 996500{9 \over {96500}}965009​ ×\times× 4 ×\times× 104 ×\times× 6 ×\times× 60 ×\times× 60

= 8.1 × 104 g

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