Aluminium is manufactured by electrolysis of molten cryolite. In an experiment, passage of 100 amperes of current for 80.4 hours resulted in the deposition of 2.425 kg of Al at cathode. For this experiment (charge on e^- = 1.602 ×10^-19 C) the correct statement(s) is/are

(1) $\text{ Coulombs passed }=80.4\times 3600\times 100=2.8944\times {10}^7$

$\text{ Weight of Al to be deposited }=\frac{2.8944\times {10}^7\times 27}{3\times 965\times {10}^2}=2700\mathrm{g}=2.7\mathrm{kgs}$

$\text{ Current efficiency }=\frac{2.425}{2.7}\times 100=89.8\text{. }$

(2) If current efficiency is 100% ,weight of Al deposited = 2.7 kg.

(3) $\text{ Moles of }\overline{\mathrm{e}}\text{ passed through the cell }=\frac{2.8944\times {10}^7}{96,500}=3\times {10}^4$

$\left(\because 1\text{ mole of }\overline{\mathrm{e}}=6\times {10}^{23} \overline{\mathrm{e}}\right)$

(4) Electronic charge = 1.6 × 10^-19 C. Since there are three +ve charges on Al³⁺ ion, charge on Al³⁺ = 3 × 1.6 × 10^-19 = 4.8 × 10^-19C.