To find the valency of copper in copper oxide, you need to consider the different forms of copper oxide and the known valency of oxygen. Copper exhibits two common valencies, resulting in two main types of copper oxide: Copper(I) oxide (Cu₂O) and Copper(II) oxide (CuO).
Determining Valency in Copper(I) Oxide (Cu₂O)
Here's how to find the valency of copper in Cu₂O:
- Identify the elements: Cu₂O consists of copper (Cu) and oxygen (O).
- Know the valency of oxygen: Oxygen typically has a valency of -2.
- Overall charge neutrality: The overall charge of the compound must be neutral (0).
- Calculate copper's valency:
- Let the valency of Cu be 'x'.
- The total positive charge from copper is 2x (since there are two copper atoms).
- The total negative charge from oxygen is -2.
- Therefore, 2x + (-2) = 0
- Solving for x, we get 2x = 2, so x = +1.
Therefore, the valency of copper in Cu₂O is +1.
Determining Valency in Copper(II) Oxide (CuO)
Here's how to find the valency of copper in CuO:
- Identify the elements: CuO consists of copper (Cu) and oxygen (O).
- Know the valency of oxygen: Oxygen typically has a valency of -2.
- Overall charge neutrality: The overall charge of the compound must be neutral (0).
- Calculate copper's valency:
- Let the valency of Cu be 'x'.
- The total positive charge from copper is x (since there is one copper atom).
- The total negative charge from oxygen is -2.
- Therefore, x + (-2) = 0
- Solving for x, we get x = +2.
Therefore, the valency of copper in CuO is +2.
In summary, copper can have a valency of +1 in Cu₂O or +2 in CuO, depending on the compound. Understanding the principle of charge neutrality and the common valency of oxygen (-2) is key to determining the valency of copper in these oxides.
