Chemical Reactions: Reactions can actually be categorized in the following 3 main groupings: 1)The Precipitation 2)The Redox 3)The Acid/Base Synthesis and Decomposition (special case acid/base OR redox)

The Precipitation You don’t need to memorize solubility rules, but you may recall from our lab work and demos……. Ex: Solutions of copper(II) nitrate and sodium phosphate are mixed 3Cu PO 4 3-  Cu 3 (PO 4 ) 2

The Precipitation: Now You Try Solutions of iron(III) chloride and lithium carbonate are mixed, resulting in a visible precipitate in a solution. Ni OH -  Ni(OH) 2 Aqueous solutions of silver nitrate and sodium chloride are mixed, resulting in the formation of a precipitate in a solution. Solutions of nickel(II) acetate and potassium hydroxide are mixed, resulting in visible precipitation in the solution.  Fe 2 (CO 3 ) 3 Ag + + Cl -  AgCl 2Fe CO 3 2-

Redox #1 1)Single replacement Magnesium metal is placed in a solution of iron(III) chloride 3Mg + 2 Fe 3+  3Mg Fe Solid potassium is added to distilled water 2 K + 2H 2 O  2K + + 2OH - + H 2 Solutions of fluorine and sodium chloride are mixed F Cl -  2F - + Cl 2

Redox #1: Now You Try A solution of sodium iodide is place in bromine water Sn 2+ + Cd  Cd 2+ + Sn A solution of silver nitrate is poured over copper metal Cadmium metal is placed in a solution of tin(II) chloride 2I - + Br 2  I 2 + 2Br - 2Ag + + Cu  2Ag + Cu 2+ Solutions of tin(II) chloride and iron(III) chloride are mixed Sn Fe 3+  Sn Fe 2+

Redox #2 Combustion butanol ( C 4 H 10 O) is burned in air C 4 H 10 O + 6 O 2  4 CO H 2 O calcium is burned in air 2Ca + O 2  2CaO

Redox #2: Now You Try Propane (C 3 H 8 ) is burned in air Ethyne (C 2 H 2 ) is burned in air C 3 H 8 + 5O 2  3 CO 2 + 4H 2 O Magnesium metal is burned in air 2Mg + O 2  2MgO 2C 2 H 2 + 5O 2  4CO 2 + 2H 2 O

Synthesis and Decomposition As Redox Now You Try Hydrogen peroxide is left in light 2H 2 O 2  O 2 + 2H 2 O Molten sodium chloride is electrolyzed 2Na + + 2Cl -  2Na + Cl 2 Lithium metal is strongly heated in nitrogen gas 3Li + N 2  2Li 3 N Aqueous sodium iodide is electrolyzed 2H 2 O + 2I -  H 2 + 2OH - + I 2

Acid/Base #1 1)Traditional: Bronsted Lowry: H + transfer Solutions of ethanoic (CH 3 COOH) acid and sodium hydroxide are mixed CH 3 COOH + OH -  H 2 O + CH 3 COO - Look for stoichiometry “excess” or “equal volumes of equimolar” A) equal volumes of equimolar solutions of sodium phosphate and hydrochloric acid are mixed H + + PO 4 3-  HPO 4 2- B) excess hydrochloric acid is added to aqueous sodium phosphate 3H + + PO 4 3-  H 3 PO 4

Acid/Base #1: Now You Try A solution of nitric acid was poured into an ammonia solution 2H + + CaCO 3  Ca 2+ + H 2 O + CO 2 Solutions of hydrochloric acid and sodium hydroxide are mixed Hydroiodic acid is poured over solid calcium carbonate H + + NH 3  NH 4 + H + + OH -  H 2 O Solutions of nitrous acid and potassium hydroxide are mixed HNO 2 + OH -  H 2 O + NO 2 - Solutions of hydrofluoric acid and methylamine are mixed HF + CH 3 NH 2  CH 3 NH F mL of 0.10 M hydrochloric acid is mixed with 5.0 mL of 0.2 M sodium phosphate 2H + + PO 4 3-  H 2 PO 4 -

Acid/Base #2 2)Anhydrides mixed in water i)Base Anhydrides Solid sodium oxide is sprinkled in water Na 2 O + H 2 O  2 Na OH - (Could also have slightly soluble hydroxides: Ca, Mg) ii) Acid anhydrides Carbon dioxide gas is bubbled through water H 2 O + CO 2  H 2 CO 3  H + + HCO 3 - (Remember strong vs. weak acids)

Synthesis and Decomposition As Anhydride Reaction 1)Decomposition: salt decomposed to acid and and base anhydrides solid calcium carbonate is heated CaCO 3  CaO + CO 2 2) Synthesis: salt synthesized when acid and base anhydrides react carbon dioxide gas is blown over solid calcium oxide CaO + CO 2  CaCO 3

Acid/Base #2: Now You Try P 4 O H 2 O  4H 3 PO 4 Solid lithium oxide is sprinkled in water Solid tetraphosphorous pentoxide is added to water Li 2 O + H 2 O  2Li + + 2OH - Iron(II) sulfite is heated strongly FeSO 3  FeO + SO 2 Dintrogen pentoxide gas is bubbled through water N 2 O 5 + H 2 O  2H + + 2NO 3 -

Acid/Base #3 3) Complex ion Formation (Technically Lewis Acid/Base) Excess concentrated ammonia is added to solid silver chloride AgCl + 2 NH 3  Ag(NH 3 ) Cl - Hints “Excess concentrated” Ligands we have seen in this class: NH 3, CN -, Cl -, OH -, SCN -.. A common algorithm: 2 times charge on metal ion

Acid/Base #3: Now You Try Excess concentrated hydrochloric acid is added to a solution of cobalt(III) nitrate Cu NH 3  Cu(NH 3 ) 4 2+ Excess concentrated solution of hydrochloric acid is added to solid silver chloride Excess concentrated ammonia is added to a solution of copper(II) chloride Co Cl -  CoCl 6 3- AgCl + Cl -  AgCl 2 - Solid aluminum hydroxide is added to concentrated potassium hydroxide Al(OH) 3 + OH -  Al(OH) 4 -

Final Thoughts When information is given pertaining to reactivity, a reaction ALWAYS occurs. Use checklist approach to categorize reaction type Remember unstable acids: H 2 CO 3, H 2 SO 3 and NH 4 OH Sulfuric acid appears as either: H + + HSO 4 - (sometimes 2H + + SO 4 2- )