When a copper vessel is exposed to moist air for long, it acquires a dull green coating. The green material is a mixture of

Question

$\begin{array}{1 1} \text{ a) Copper oxide and Copper Nitrate } \\ \text{b) Copper hydroxide & Copper Carbonate} \\ \text{ c) Copper carbonate and Copper sulfate } \\ \text{d) Copper hydroxide and Copper Nitrate} \end{array}$