The reactions of halide ions with silver nitrate.

• What is the test where you add nitric acid and silver nitrate.

  To test for which halide ion is present. The test solution is made acidic with nitric acid, and then silver nitrate solution is added dropwise.
• Why is nitric acid added when testing reactions of halide ions with silver nitrate

  The role of nitric acid is to react with any carbonates present to prevent formation of the precipitate Ag2CO3. This would mask the desired observations:

  2 HNO3 + Na2CO3 -> 2 NaNO3 + H2O + CO2
• The reactions of halide ions with silver nitrate results.

  Fluorides produce no precipitate.

  Chlorides produce a white precipitate

  Ag+(aq) + Cl- (aq) -> AgCl(s)

  Bromides produce a cream precipitate

  Ag+(aq) + Br- (aq) -> AgBr(s)

  Iodides produce a pale yellow precipitate

  Ag+(aq) + I- (aq) -> AgI(s
• What happens when silver chloride reacts with dilute ammonia?

  It forms a complex ion.
• What is the chemical equation for silver chloride dissolving in dilute ammonia?

  AgCl(s) + 2NH3(aq) -> [Ag(NH3)2]+ (aq) + Cl- (aq)
• What type of solution is formed when silver chloride dissolves in dilute ammonia?

  A colourless solution.
• What happens when silver bromide reacts with concentrated ammonia?

  It forms a complex ion.
• What is the chemical equation for silver bromide dissolving in concentrated ammonia?

  AgBr(s) + 2NH3(aq) -> [Ag(NH3)2]+ (aq) + Br- (aq)
• What type of solution is formed when silver bromide dissolves in concentrated ammonia?

  A colourless solution.
• Why does silver iodide not react with ammonia?

  It is too insoluble.