Final answer:
To find the mass of CaCl₂ in a solution, multiply the molarity by the volume in liters to get the moles, then multiply the moles by the molar mass of CaCl₂. For a 0.200-M, 250 mL solution, this results in 5.549 grams of CaCl₂.
Step-by-step explanation:
To calculate the amount of calcium chloride in a given volume and molarity of solution, you use the formula: molarity (M) = moles of solute/liters of solution. First, find the number of moles of CaCl₂ in the solution by multiplying the molarity by the volume in liters. Next, calculate the mass of CaCl₂ by multiplying the amount of moles by the molar mass of CaCl₂.
For the example provided, we have a 0.200 M solution of calcium chloride and the volume is 250.0 mL which is 0.250 liters. So, multiply 0.200 M by 0.250 L to get the number of moles of CaCl₂:
- moles CaCl₂ = 0.200 mol/L × 0.250 L = 0.050 moles
Now, multiply the number of moles by the molar mass (110.98 g/mol) to find the mass:
- mass of CaCl₂ = 0.050 moles × 110.98 g/mol = 5.549 g
Hence, 250.0 mL of a 0.200-M solution of calcium chloride contains 5.549 grams of CaCl₂.