1. Effervescence: Initially, there will be a reaction between the copper oxide (CuO) and the hydrochloric acid (HCl), leading to the formation of copper chloride (CuCl2) and water (H2O). This reaction is represented by the following chemical equation:
CuO + 2HCl → CuCl2 + H2O
As the acid reacts with the copper oxide, bubbles of a colorless gas will be produced. This gas is hydrogen chloride (HCl) gas, which is formed as a byproduct of the reaction. The effervescence indicates the release of the HCl gas.
2. Color Change: As the reaction proceeds, the copper oxide, which is initially black in color, will start to dissolve in the hydrochloric acid solution. This will result in a change in the color of the solution. The solution will turn green due to the formation of copper(II) chloride (CuCl2).
3. Formation of Salt: As the reaction continues, copper(II) chloride will dissolve in the water present in the beaker, forming a blue-green colored solution. This solution contains copper(II) ions (Cu2+) and chloride ions (Cl-).
Overall, the reaction between dilute hydrochloric acid and copper oxide results in the formation of copper(II) chloride, water, and the release of hydrogen chloride gas. The effervescence, color change, and formation of a colored solution are the key observations that can be made during this reaction.
