What is the molarity of a solution prepared by dissolving 8.0 g of CaO in enough water to make 0.20 L of solution? (Molar mass of CaO = 56.08 g/mol)

• A. 0.40 M
• B. 2.0 M
• C. 0.71 M
• D. 1.4 M

Answer: (C)

Verified step by step guidance

1. Identify the given information: mass of CaO = 8.0 g, volume of solution = 0.20 L, and molar mass of CaO = 56.08 g/mol.
2. Calculate the number of moles of CaO using the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{8.0\ \text{g}}{56.08\ \text{g/mol}}\).
3. Use the definition of molarity, which is moles of solute per liter of solution: \(M = \frac{\text{moles of solute}}{\text{volume of solution in liters}}\).
4. Substitute the values into the molarity formula: \(M = \frac{\text{moles calculated in step 2}}{0.20\ \text{L}}\).
5. Perform the division to find the molarity of the CaO solution.