Write down the formulae for: • Silver chloride • Sodium hydroxide • Ammonium nitrate • Copper carbonate • Magnesium hydroxide • Potassium sulfate
Write down the formulae for: • Aluminium hydroxide • Copper hydrogen carbonate • Zinc bicaronate • Sodium sulfate • Potassium carbonate • Ammonium chloride
Write down the formulae for: Sodium nitrate Zinc sulfate Lithium carbonate Sodium phosphate Copper hydroxide Calcium nitrate Aluminium Oxide
Copy and fill in the blanks When an atom loses one or more electrons, it becomes a ________. When an atom gains one or more electrons, it becomes an _______. When a cation combines with an anion, they become an ______ _________. Some ionic compounds are “_______”, which means they dissolve in water.
Two ionic solutions, potassium hydroxide and copper sulfateare mixed together. Name the four ions that are present in the mixture. Would precipitate form? Give the name of the precipitate. Write down the formula of the precipitate. Give the names of the spectator ions.
Precipitation Reaction Some ionic compounds are soluble (dissolves in water) whereas some are insoluble (does not dissolve in water). Insoluble ionic compounds can form when two solutions of soluble compounds are mixed. The cation from one solution and the anion from the other solution can react to form precipitate, an insoluble solid.
Solubility • Soluble – dissolves in water (the ionic bondbetween the cation and the anion breaks) • Insoluble – does not dissolve (theionic bonddoes not break)
Soluble or insoluble? • Silver chloride • Sodium hydroxide • Ammonium nitrate • Copper carbonate • Magnesium hydroxide
Soluble or insoluble? • Copper Chloride • Copper Hydroxide • Magnesium Hydroxide • Magnesium Sulfate • Zinc Sulfate • Aluminium Sulfate - Soluble - Insoluble - Insoluble - Soluble - Soluble - Soluble
What about these…? • Sodium Chloride • Sodium Iodide • Sodium Hydroxide • Sodium Nitrate • Sodium Carbonate • Sodium Sulfate - Soluble - Soluble - Soluble - Soluble - Soluble - Soluble
What about these…? • Sodium Chloride • Sodium Iodide • Sodium Hydroxide • Sodium Nitrate • Sodium Carbonate • Sodium Sulfate Every ionic compound that contains Sodium ion is soluble
Solubility Rules • Sodium, Potassium, Ammonium ions are ALL SOLUBLE • Nitrate ion is ALWAYS SOLUBLE • Chloride ion is always SOLUBLE, EXCEPT silver chloride and lead chloride • Sulfate ion is always SOLUBLE EXCEPT lead sulfate, calcium sulfateand barium sulfate • Carbonate ion is always INSOLUBLE, EXCEPT those of Group 1 and ammonium • Hydroxide ion is always INSOLUBLE, EXCEPT those of Group 1
Solubility Rules (for experts) • All Group 1 compounds are soluble e.g. Na2CO3, KOH • All nitrate, NO3- compounds are soluble e.g. Cu(NO3)2 • Most sulfates are soluble e.g. FeSO4 • Most halides are soluble e.g. FeCl3, CuBr2 • Insoluble sulfates are CaSO4 , BaSO4, PbSO4 • Insoluble halides are those of Ag+, Pb2+ e.g. AgCl, AgI • All carbonates , CO32-, are insoluble e.g. BaCO3EXCEPT those of Group 1 • All oxides, hydroxides are insoluble e.g. CuO, Al(OH)3EXCEPT those of Group 1
Cations Cameron = Barium ion (Ba2+) Tom = Sodium ion (Na+) Anions Mary = Chloride ion (Cl-) Alice = Carbonate ion (CO32-)
Barium Chloride = soluble The bond between Cameron and Mary is WEAK. Sodium Carbonate = soluble The bond between Tomand Alice is WEAK. Sodium Chloride = soluble The bond between Tomand Mary is WEAK. Barium Carbonate = Insoluble The bond between Cameron and Alice is STRONG.
Let’s say that we have these two couples (ionic compounds). • Tom & Alice (sodium carbonate) • Cameron & Mary (barium chloride) • Question: • If we dump these couples into a swimming pool… what would happen to them?
Barium Carbonate = Insoluble Cameron and Alice forms ionic bond and become insoluble “Precipitate”. Sodium Chloride = soluble Tom and Mary just chill out and spectate. They become “Spectator Ions”.
When you mix two ionic solutions, you get TWO cations and TWO anions in the solution. (four ‘separate’ ions in total) If you can find an “insoluble” match between any of these four ions, you have precipitate. The ions that do not form precipitate are spectator ions.
Investigation Aim: to observe the formation of precipitates by mixing solutions of various ions
Precipitation Reaction - EXAMPLES Is copper sulfate soluble or insoluble? Is sodium hydroxide soluble or insoluble? What would happen if the two are mixed together? Copper Sulfate + Sodium Hydroxide
Practical – Mystery Solution “X” Aim: To find out which ionic compound has been dissolved in the unknown solution