Answer: Approximately 545.12 grams of zinc chloride
Explanation: To determine the mass of zinc chloride needed to make a 4.0 Molar solution with a total volume of 1.0 L, we need to use the formula:
Molarity (M) = Moles of solute / Volume of solution (in liters)
Rearranging the formula, we can solve for the moles of solute:
Moles of solute = Molarity × Volume of solution
Given:
Molarity (M) = 4.0 M
Volume of solution = 1.0 L
Moles of solute = 4.0 M × 1.0 L = 4.0 moles
Now, to find the mass of zinc chloride, we need to know its molar mass. The molar mass of zinc chloride (ZnCl2) can be calculated as follows:
Molar mass of ZnCl2 = (Atomic mass of zinc) + 2 × (Atomic mass of chlorine)
Molar mass of ZnCl2 = (65.38 g/mol) + 2 × (35.45 g/mol)
Molar mass of ZnCl2 ≈ 136.28 g/mol
Finally, we can calculate the mass of zinc chloride needed using the equation:
Mass of zinc chloride = Moles of solute × Molar mass of zinc chloride
Mass of zinc chloride = 4.0 moles × 136.28 g/mol ≈ 545.12 g
Approximately 545.12 grams of zinc chloride