Calculate formula mass and the molar mass of each of the fol- lowing formula units: \( \begin{array}{lll}\text { a. } \mathrm{NaCl} & \text { b. } \mathrm{Na}_{2} \mathrm{SO}_{4} & \text { c. } \mathrm{Fe}_{3}\left(\mathrm{PO}_{4}\right)_{2}\end{array} \)

To calculate the formula mass and molar mass of each compound, we need to know the atomic masses of the constituent elements. Here’s a quick breakdown: For sodium chloride (\( \text{NaCl} \)): - Sodium (Na) = 22.99 g/mol - Chlorine (Cl) = 35.45 g/mol Formula mass = 22.99 + 35.45 = 58.44 g/mol. For sodium sulfate (\( \text{Na}_{2}\text{SO}_{4} \)): - Sodium (Na) = 22.99 g/mol, and there are 2 sodium atoms: 2 × 22.99 = 45.98 g/mol - Sulfur (S) = 32.07 g/mol - Oxygen (O) = 16.00 g/mol, and there are 4 oxygen atoms: 4 × 16.00 = 64.00 g/mol Formula mass = 45.98 + 32.07 + 64.00 = 142.05 g/mol. For iron(III) phosphate (\( \text{Fe}_{3}\text{(PO}_{4}\text{)}_{2} \)): - Iron (Fe) = 55.85 g/mol, and there are 3 iron atoms: 3 × 55.85 = 167.55 g/mol - Phosphorus (P) = 30.97 g/mol, and there are 2 phosphorus atoms: 2 × 30.97 = 61.94 g/mol - Oxygen (O) = 16.00 g/mol, and there are 8 oxygen atoms: 8 × 16.00 = 128.00 g/mol Formula mass = 167.55 + 61.94 + 128.00 = 357.49 g/mol. In summary: - \( \text{NaCl} \) = 58.44 g/mol - \( \text{Na}_{2}\text{SO}_{4} \) = 142.05 g/mol - \( \text{Fe}_{3}\text{(PO}_{4}\text{)}_{2} \) = 357.49 g/mol