# Question #bd857

$3.58 \setminus \times {10}^{23}$ molecules of oxygen will be formed.
The molecular weight of $K C l {O}_{3}$ (one atom of potassium + one of chlorine + three of oxygen) is 122.55 g/mol. So 48.5 g of $K C l {O}_{3}$ is 48.5/122.55=0.396 mol.
The balanced equation shows we have 3 moles of oxygen for every 2 moles of $K C l {O}_{3}$. So the 0.396 mol of $K C l {O}_{3}$ will make 0.594 mol of oxygen. Each mole has $6.02 \setminus \times {10}^{23}$ molecules, and $0.594 \setminus \times 6.02 \setminus \times {10}^{23} = 3.58 \setminus \times {10}^{23}$.