What is the molarity of a solution prepared by dissolving 16.4 g of CaSO_4 in 500.0 mL of solution? (Molar mass of CaSO_4 = 136.1 g/mol)

• A. 0.482 M
• B. 0.120 M
• C. 0.060 M
• D. 0.241 M

Answer: (D)

Verified step by step guidance

1. Identify the given information: mass of CaSO_4 = 16.4 g, volume of solution = 500.0 mL, and molar mass of CaSO_4 = 136.1 g/mol.
2. Convert the volume of the solution from milliliters to liters because molarity is expressed in moles per liter. Use the conversion: \$1\, \text{L} = 1000\, \text{mL}\(, so \)V = \frac{500.0}{1000} = 0.500\, \text{L}$.
3. Calculate the number of moles of CaSO_4 using the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{16.4\, \text{g}}{136.1\, \text{g/mol}}\).
4. Use the definition of molarity, which is moles of solute per liter of solution: \(M = \frac{\text{moles of CaSO}_4}{\text{volume in liters}}\).
5. Substitute the values from the previous steps into the molarity formula to find the molarity of the solution.