Answer : The number of moles of oxygen atoms are 10 moles.
Explanation : Given,
Moles of [tex]KMnO_4[/tex] = 2.50 moles
By the stoichiometry we can say that in [tex]KMnO_4[/tex], there are 1 moles of potassium atom, 1 mole of manganese atom and 4 moles of oxygen atoms.
That means,
As, 1 mole of [tex]KMnO_4[/tex] contains 4 moles of oxygen atoms
So, 2.50 mole of [tex]KMnO_4[/tex] contains [tex]2.50\times 4=10[/tex] moles of oxygen atoms
Therefore, the number of moles of oxygen atoms are 10 moles.