How many moles of oxygen atoms are present in 132.2 g of MgSO_4?

• A. 5.30 moles
• B. 2.65 moles
• C. 0.83 moles
• D. 1.65 moles

Answer: (B)

Verified step by step guidance

1. Identify the chemical formula of the compound given: MgSO_4. This tells us the compound contains 1 magnesium (Mg), 1 sulfur (S), and 4 oxygen (O) atoms per formula unit.
2. Calculate the molar mass of MgSO_4 by summing the atomic masses of each element multiplied by their subscripts: \(\text{Molar mass} = (1 \times M_{Mg}) + (1 \times M_{S}) + (4 \times M_{O})\) where \(M_{Mg}\), \(M_{S}\), and \(M_{O}\) are the atomic masses of magnesium, sulfur, and oxygen respectively.
3. Determine the number of moles of MgSO_4 in 132.2 g by using the formula: \(\text{moles of MgSO}_4 = \frac{\text{mass of MgSO}_4}{\text{molar mass of MgSO}_4}\).
4. Since each mole of MgSO_4 contains 4 moles of oxygen atoms, calculate the moles of oxygen atoms by multiplying the moles of MgSO_4 by 4: \(\text{moles of O atoms} = 4 \times \text{moles of MgSO}_4\).
5. This final value gives the number of moles of oxygen atoms present in 132.2 g of MgSO_4.