Silver ions can be precipitated from aqueous solutions by the addition of aqueous chloride: Ag⁺(aq) + Cl^- (aq) → AgCl (s)
Silver chloride is virtually insoluble in water so that the reaction appears to go to completion.How many grams of solid NaCl must be added to 25.0 mL of 0.149 M AgNO₃ solution to completely precipitate the silver?

Question

Quizplus · Accepted Answer

Step 1: Write the balanced chemical equation for the reaction occurring between AgNO3 and NaCl:

AgNO3 (aq) + NaCl (aq) → AgCl (s) + NaNO3 (aq)

Step 2: Determine the moles of AgNO3 present in the solution:

0.149 M = 0.149 moles/L
0.0250 L x 0.149 mol/L = 0.003725 mol AgNO3

Step 3: Use the mole ratio from the balanced equation to determine the moles of NaCl needed to react completely with the AgNO3:

1 mole AgNO3 reacts with 1 mole NaCl
0.003725 mol AgNO3 x 1 mol NaCl/1 mol AgNO3 = 0.003725 mol NaCl

Step 4: Convert the moles of NaCl to grams:

0.003725 mol NaCl x 58.44 g/mol = 0.218 g NaCl

Therefore, the answer is (C) 0.218.

Silver Ions Can Be Precipitated from Aqueous Solutions by the Addition