Here's how to determine the moles of oxygen (O) in one mole of CuSO₄:

1. Identify the Chemical Formula:

* CuSO₄ represents copper(II) sulfate.

2. Determine the Number of Oxygen Atoms:

* The subscript "4" after the oxygen (O) indicates that there are 4 oxygen atoms in each molecule of CuSO₄.

3. Moles of Oxygen per Mole of CuSO₄:

* Since there are 4 moles of oxygen atoms for every 1 mole of CuSO₄, there are 4 moles of O in one mole of CuSO₄.