In hydrometallurgical process for extraction of copper. The correct statement is/are:-
1.The copper ore is leached with bacteria or by using sulphuric acid.
2.Hydrometallurgical process is ecofriendly because the sulphur content of the ore is oxidised to sulphate instead of liberating pollutant `O_(2)`gas.
3.From the solution copper is recovered by using more electropositive metal like zinc or scrap iron.
4.The copper obtained is of high pure.