Info: 1. Obtain 15.0 mL each of silver nitrate and sodium chloride solutions . A
ID: 1032840 • Letter: I
Question
Info: 1. Obtain 15.0 mL each of silver nitrate and sodium chloride solutions . Add approximately 25 mL of 6 M aqueous ammonia 2. Add approximately 25 mL of 6 M nitric acid and stir. Q: a. Write the net ionic equation for the reaction (which involves one of the species in the reaction that you've just written) that occurs when aqueous ammonia is added to the beaker (1). According to Le Châtelier's principle, why does the precipitate dissolve upon addition of ammonia? b. Write the net ionic equation for the reaction that occurs when nitric acid is added to the beaker (2). Explain why the precipitate reappears upon addition of nitric acid.Explanation / Answer
1. When AgNO3 and NaCl solutions are mixed, a precipitate of AgCl will be formed which will dissolve in aq. NH3 due to the formation of Ammonical silver cation
AgNO3(aq) + NaCl(aq) -----> AgCl(s) + NaNO3(aq)
AgCl(s) + 2NH3(aq) ----> [Ag(NH3)2]Cl(aq)
Net ionic equation is
Ag+(aq) + 2NH3(aq) ==== [Ag(NH3)2]^+(aq)
b) When HNO3 is added to the above silver complex, again it forms AgCl and hence precipitate reappears
2HNO3 + [Ag(NH3)2]^+ --> AgCl(s) + 2NH4+(aq) + 2NO3^- (aq)
Net equation is
Ag+(aq) + Cl(aq) -----> AgCl(s)