JAMB Chemistry 2015 Paper

Concept:Electricity needed for discharge depends on the total charge carried by the ions present.Explanation:Quantity of electricity used = amount in moles $\times$ charge on one ion.Calculate for each option:A: $2.0 \times (+3) = 6.0$ Faraday units.B: $2.5 \times (+2) = 5.0$ Faraday units.C: $3.0 \times 1 = 3.0$ Faraday units.D: $4.0 \times 1 = 4.0$ Faraday units.The largest quantity of electricity is $6.0$ Faraday units, which is required by option A.Answer:A. 2.0 mole of $\mathrm{Q}^{3+}$