Explain how to prepare 0.250 L of a 0.500 M CuSO4 solution. 1. Measure out 0.500 moles of CuSO4 solid 2. Measure out 20.0 g of CuSO4 solid 3. Measure out 0.500 moles of CuSO4 solid and add water until a volume of 1.0 L is reached 4. Measure out 20.0 g of CuSO4 solid and add water until a volume of 250 mL is reached