Which of the following statements are correct?
(i) A depressant prevents certain type of particle to come to the froth.
(ii) Copper matte contains Cu2S and ZnS.
(iii) The solidified copper obtained from reverberatory furnace has blistered
appearance due to evolution of SO2 during the extraction.
(iv) Zinc can be extracted by self-reduction.
NCERT Class XII
Chemistry - Exemplar Problems
Chapter 6. General Principles and Processes of Isolation of Elements