Why does copper oxide not dissolve in water
The Correct Answer and Explanation is:
Copper oxide (CuO) does not dissolve in water because of its chemical properties and the nature of the bonding in the compound. Copper oxide is an ionic compound that forms a crystalline structure consisting of copper (Cu²⁺) and oxide (O²⁻) ions held together by strong electrostatic forces of attraction. These forces are difficult to overcome by the interaction with water molecules alone.
To understand why copper oxide does not dissolve in water, we need to consider two factors: polarity and solubility.
- Polarity of Water: Water molecules are polar, meaning they have a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom. Water is an effective solvent for ionic compounds that can dissociate into ions, like sodium chloride (NaCl). For an ionic compound to dissolve in water, the positive and negative ions must interact with the water molecules, with the water molecules surrounding and separating the ions.
- Bond Strength in Copper Oxide: Copper oxide, however, has a high lattice energy due to the strong ionic bonds between copper ions (Cu²⁺) and oxide ions (O²⁻). This high lattice energy makes it difficult for water molecules to break apart the ions and dissolve the compound. The forces between the ions in copper oxide are stronger than the interactions that water molecules can provide.
As a result, copper oxide does not readily dissociate in water. Unlike compounds like sodium chloride, which dissolve easily due to their relatively weaker ionic bonds, copper oxide remains insoluble because the water molecules are unable to disrupt the strong ionic lattice and break the compound into individual ions.
In summary, copper oxide does not dissolve in water because of the strong electrostatic attraction between its ions, which water molecules cannot overcome. This inability to dissociate into free ions makes it insoluble in water.
