How many electrons would be required to deposit 6.35 g of copper at the cathode during the electrolysis of an aqueous solution of copper sulphate ? (Atomic mass of copper =63.5 u $\;N_{A}\;$ = Avogadro's constant) :

Question

$(a)\;\large\frac{N_{A}}{20}\qquad(b)\;\large\frac{N_{A}}{10}\qquad(c)\;\large\frac{N_{A}}{5}\qquad(d)\;\large\frac{N_{A}}{2}$