Question
A and B are two ores of copper.
A undergoes calcination to form a solid, CO2(g) and O2(g)
B undergoes roasting to form a solid and a gas C which turns acidified K2Cr2O7 to green solution.
B also reacts with dil HCl to form a solid and gas D which turns lead acetate solution black. D also reacts with C to form colloidal sulphur in the presence of moisture.
The nature of the gas (D) and hybridization of the central atom is respectively: