Which of the following reactions is an example of autoreduction ?
(i)
(ii)
(iii)
(iv)
In this reaction reduction of copper (I) oxide by copper (I) sulphide takes place. Since, copper is reduced by itself, this process is known as auto-reduction and the solidified copper so, obtained is known as blister copper. We get the copper metal on reaction of sulphide ore of copper with its oxide.