Copper produces a red oxide, $\text{Cu}_2\text{O}$, and a black oxide, $\text{CuO}$. When a catalyst is present, aqueous hydrogen peroxide, $\text{H}_2\text{O}_2$, decomposes to make water. The black oxide contains copper in a .....1..... oxidation state than the red oxide does. When water is formed, hydrogen peroxide is .....2...... . Which words correctly fill gaps 1 and 2?
- Ahigher; reduced
- Bhigher; oxidised
- Clower; reduced
- Dlower; oxidised