How to Calculate Mass of NaCl Needed to Precipitate Silver Chloride

Question:

What is the process to determine the mass of solid NaCl required to completely precipitate silver from a solution containing AgNO₃?

Answer:

To determine the mass of NaCl needed to completely precipitate silver from a solution of AgNO₃, you have to consider the stoichiometry of the reaction between AgNO₃ and NaCl.

When AgNO₃ reacts with NaCl, silver chloride (AgCl) precipitates out while sodium nitrate (NaNO₃) remains in solution. The reaction can be represented by the equation:
AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

To calculate the mass of NaCl needed, first, determine the moles of AgNO₃ present in the solution by using its concentration and volume. Since the stoichiometry of the reaction shows a 1:1 ratio between AgNO₃ and AgCl, the moles of AgNO₃ will be equal to the moles of AgCl precipitated.

Once you have the moles of AgCl, you can then convert it to grams by utilizing the molar mass of AgCl. This will give you the amount of NaCl required to completely precipitate the silver.

By following this process, you can accurately calculate the mass of solid NaCl needed to ensure the completion of the reaction and the precipitation of silver chloride from the AgNO₃ solution.