Question

When the light green colour copper carbonate is heated, it changes into copper oxide. What is the residue it leaves behind and what is the gas released after this chemical change?

Answer 1

Copper carbonate on heating dissociates to form two compounds , copper oxide and carbon dioxide . CuCO3 -----> CuO ( black )+ CO2 . On heating Copper carbonate , a black residue is formed and a gas is released which turns lime water milky . Thus , we can conclude that the gas evolved is carbon dioxide .