Question

Malachite decomposed to give \(A + CO_2 + H_2O\) and compound \(A\) on reduction with carbon gives \(CO + B\). Here, \(A\) and \(B\) are

• A. CuO, Cu
• B. Cu\(_2\)O, CuO
• C. Cu\(_2\)O, Cu
• D. CuCO\(_3\), Cu

Hint:

Malachite on heating gives oxide, which on reduction gives metal.

Answer 1

The Correct Option is C

Concept: Malachite is a basic copper carbonate: \[ CuCO_3 \cdot Cu(OH)_2 \]

Step 1: Thermal decomposition.
\[ CuCO_3 \cdot Cu(OH)_2 \xrightarrow{\Delta} Cu_2O + CO_2 + H_2O \]

Step 2: Reduction with carbon.
\[ Cu_2O + C \xrightarrow{\Delta} 2Cu + CO \]

Step 3: Conclusion.
\[ A = Cu_2O,\quad B = Cu \]