Question

A reddish brown vessel developed a green colored solid X when left open in air for a long time. When reacted with dil H2SO4 , it forms a blue colored solution along with brisk effervescence due to colourless & odourless gas Z. X decomposes to form black colored oxide Y of a reddish brown metal along with gas Z, Identify X, Y, & Z.

Answer 1

X is CuCo3.Cu(OH)2
Y is CuO
Z is CO2


Hope it helps.

Answer 2

X is Copper Carbonate (CuCO3) and ,
Y is Copper Oxide (CuO)
Z is Carbon dioxide evolved from reaction .

I hope it will become helpful to u