Name Test Tube 1: HClNH3 Test Tube 2: NaOHExcess
Aluminum 3+ No precipitate Slightly milky Dissolves
Ammonium + No Precipitate No precipitate Calcium 2+ No Precipitate Milky white precipitate Precipitate does not dissolve
Copper 2+ No precipitate Became much darker blue and milky Iron 3+ Brighter yellow Orange precipitate that then dissolves Lead 2+ Milky white precipitate Precipitate gets more milky Silver + Milky white precipitate Precipitate gets more milky with ammonium Zinc 2+ No precipitate Milky white precipitate Precipitate dissolves
Unknown No precipitate No precipitate Name Test Tube 3: NH3 Excess Test Tube 4: Confirmation
Aluminum 3+ Milky More milky Turns dark pink
Ammonium + No precipitate Changes color of paper
Calcium 2+ Milky white precipitate appears
Copper 2+ Turned dark purple
Iron 3+ Turns dark blue
Lead 2+ Turns bright yellow
Silver + Milky white, disappeared then reappeared
Zinc 2+ Milky white precipitate Precipitate dissolves No precipitate
Unknown Milky white precipitate Precipitate does not dissolve Zinc
Questions:
Write net ionic equations for all reactions that produce a precipitate
Iron & HCl1. Fe3+3HCl- FeCl3+3H
2. Pb2+2HCl- PbCl2+2H
3. Ag+HCl- AgCl+H4. Al(NO3)3 + 3NaOH = Al(OH)3+3NaNO3
5. Zinc & NH36. Al3+3NaOH Al+3NaNO3
7. 2Ca+ + 2NaOH Ca(OH)2 + 2NaNO3
8. 2 NaOH + Cu Cu2 + 2OH
9. Zn2+ 2NaOH Zn(OH)2+2Na
Identify the cations that precipitate with hydrochloric acid and dissolve in the presence of ammonia
-Iron
Identify the cations that precipitate with hydrochloric acid and do not redissolve in the presence of ammonia
-SILVER AND LEAD
Identify the cations that precipitate upon addition of two or three drops of sodium hydroxide but re-dissolve upon addition of excess sodium hydroxide.
-Aluminum, zinc
Identify the cations that precipitate upon addition of two or three drops of sodium hydroxide and are not affected by additional sodium