Final answer:
The correct setup to calculate the volume of a 0.250 M CaCl2 solution that contains 39.5 g of CaCl2 is to first convert the mass of CaCl2 to moles using its molar mass, then divide by the molarity to find the volume in liters.
Step-by-step explanation:
The proper setup to find the volume of a 0.250 M CaCl2 solution that contains 39.5 g of CaCl2 is based on the relationship between molarity, volume, and moles of solute. First, the molar mass of CaCl2 (110.98 g/mol) is used to convert the mass of solute into moles. Then, the molarity (M) which is moles of solute per liter of solution, is used to find the volume.
The volume (V) of the solution can be calculated using the formula:
V = moles of CaCl2 / Molarity (M)
The number of moles of CaCl2 is found by dividing the mass (39.5 g) by the molar mass of CaCl2 (110.98 g/mol). To find the volume in liters, the moles are then divided by the molarity (0.250 M). So, the correct setup is:
V = (39.5 g / 110.98 g/mol) / 0.250 M