Copper can best be purified by?

A. roasting the impure copper in a blast furnace
B. heating the oxide with coke
C. electrolyzing a copper (ll) salt solution using the impure copper as the anode
D. converting the impure copper to a trioxonitrate (V)
E. washing the impure copper with sodium hydroxide solution

Correct Answer:

Option C – electrolyzing a copper (ll) salt solution using the impure copper as the anode