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प्रश्न
What is the quantity of electricity in Coulombs required to produce 4.8 g of Mg from molten MgCl2? How much Ca will be produced if the same amount of electricity was passed through molten CaCl2? (Atomic mass of Mg = 24 u, atomic mass of Ca = 40 u).
उत्तर
\[\ce{Mg^{2+} + 2e- -> Mg}\]
1 mole of magnesium ions gains two moles of electrons or 2F to form 1 mole of Mg 24 g Mg requires 2F electricity.
4.8 g Mg requires `2 × 4.8/24` = 0.4F = 0.4 × 96500 = 38600 C
\[\ce{Ca^{2+} + 2e^{-} -> Ca}\]
2F electricity is required to produce 1 mole = 40 g Ca
0.4F electricity will produce 8 g Ca.
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