To determine the chloride content of an unknown soluble chloride salt, a student dissolves 0.4250 g of the salt in water and adds excess 0.10 M AgNO3. A white precipitate forms, which is filtered onto pre-weighed filter paper, washed with cold water, and dried to constant mass. Mass of dried precipitate = 0.8610 g.
What is the mass percent of chloride in the unknown salt?
- A
33.5%
- B
75.0%
- C
67.0%
- Dcheck_circle
50.1%
Explanation
Moles AgCl = 0.8610/143.32 = 6.008e-3 mol = moles Cl-. Mass Cl = 6.008e-3 * 35.45 = 0.2130 g. % Cl = 0.2130/0.4250 = 50.1%.