Question

In the second experiment, a student is given 2.94 g of a mixture containing anhydrous MgCl₂ and KNO₃. To determine the percentage by mass of MgCl₂ in the mixture, the student uses excess AgNO₃(aq) to precipitate the chloride ion as AgCl(s).

(d) Starting with the 2.94 g sample of the mixture dissolved in water, briefly describe the steps necessary to quantitatively determine the mass of the AgCl precipitate.

Answer 1

To quantitatively determine the mass of AgCl precipitate, dissolve the mixture in water, add AgNO3 to precipitate the chloride ion as AgCl, separate and wash the precipitate, then dry and weigh it.

Step-by-step explanation:

To quantitatively determine the mass of the AgCl precipitate, the student can follow these steps:

1. Dissolve the 2.94 g sample of the mixture in water to form a solution.
2. Add excess AgNO3(aq) to the solution to precipitate the chloride ion as AgCl(s).
3. Decant or filter the solution to separate the precipitate.
4. Wash the precipitate with water to remove any remaining impurities.
5. Dry the precipitate to remove any water.
6. Weigh the mass of the dried AgCl precipitate.