3 faraday of electricity is passed through molten Al2O3 , aqueous solution of CuSO4 and molten NaCl taken in three different electrolytic cells. The amount of Al, Cu and Na deposited at the cathodes will be in the ratio of:
Correct answer: C. 1 mole : 1.5 mole : 3 mole
- A. 1 mole : 2 mole : 3 mole
- B. 3 mole : 2 mole : 1 mole
- C. 1 mole : 1.5 mole : 3 mole
- D. 1.5 mole : 2 mole : 3 mole
Explanation
According to Faraday's laws of electrolysis, the amount of a substance deposited at the cathode is proportional to the charge passed through the electrolyte and inversely proportional to the charge on the ion. For Al2O3, CuSO4, and NaCl:Al requires 3 moles of electrons to deposit 1 mole of Al.Cu requires 2 moles of electrons to deposit 1 mole of Cu.Na requires 1 mole of electrons to deposit 1 mole of Na.Thus, with 3 Faradays of electricity, the amounts deposited will be in the ratio of 1:1.5:3 for Al, Cu, and Na, respectively. This makes option C correct, while the other options do not align with the law.
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