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 PrecipitationYou 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

3Cu2+ + 2PO43- Cu3(PO4)2

The Precipitation: Now You Try

Solutions of iron(III) chloride and lithium carbonate are mixed, resulting in a visible precipitate in a solution.

Ni2+ + 2OH- 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.

Fe2(CO3)3

Ag+ + Cl- AgCl

2Fe3+ + 3CO32-

Redox #11) Single replacementMagnesium metal is placed in a solution of iron(III) chloride

3Mg + 2 Fe3+ 3Mg2+ + 2Fe

Solid potassium is added to distilled water

2K + 2H2O 2K+ + 2OH- + H2

Solutions of fluorine and sodium chloride are mixed

F2 + 2 Cl- 2F- + Cl2

Redox #1: Now You Try

A solution of sodium iodide is place in bromine water

Sn2+ + Cd Cd2+ + Sn

A solution of silver nitrate is poured over copper metal

Cadmium metal is placed in a solution of tin(II) chloride

2I- + Br2 I2 + 2Br-

2Ag+ + Cu 2Ag + Cu2+

Solutions of tin(II) chloride and iron(III) chloride are mixed

Sn2+ + 2Fe3+ Sn4+ + 2Fe2+

Redox #2

Combustionbutanol (C4H10O) is burned in air

C4H10O + 6 O2 4 CO2 + 5 H2O

calcium is burned in air

2Ca + O2 2CaO

Redox #2: Now You TryPropane (C3H8 ) is burned in air

Ethyne (C2H2) is burned in air

C3H8 + 5O2 3 CO2 + 4H2O

Magnesium metal is burned in air

2Mg + O2 2MgO

2C2H2 + 5O2 4CO2 + 2H2O

Synthesis and Decomposition As RedoxNow You Try

Hydrogen peroxide is left in light

2H2O2 O2 + 2H2O

Molten sodium chloride is electrolyzed

2Na+ + 2Cl- 2Na + Cl2

Lithium metal is strongly heated in nitrogen gas

3Li + N2 2Li3N

Aqueous sodium iodide is electrolyzed

2H2O + 2I- H2 + 2OH- + I2

Acid/Base #11) Traditional: Bronsted Lowry: H+ transfer

Solutions of ethanoic (CH3COOH) acid and sodium hydroxide are mixedCH3COOH + OH- H2O + CH3COO-

Look for stoichiometry“excess” or “equal volumes of equimolar”

A) equal volumes of equimolar solutions of sodium phosphate and hydrochloric acid are mixed H+ + PO4

3- HPO42-

B) excess hydrochloric acid is added to aqueous sodium phosphate 3H+ + PO4

3- H3PO4

Acid/Base #1: Now You Try

A solution of nitric acid was poured into an ammonia solution

2H+ + CaCO3 Ca2+ + H2O + CO2

Solutions of hydrochloric acid and sodium hydroxide are mixed

Hydroiodic acid is poured over solid calcium carbonate

H+ + NH3 NH4+

H+ + OH- H2O

Solutions of nitrous acid and potassium hydroxide are mixed

HNO2 + OH- H2O + NO2-

Solutions of hydrofluoric acid and methylamine are mixed

HF + CH3NH2 CH3NH3+ + F-

20. mL of 0.10 M hydrochloric acid is mixed with 5.0 mL of 0.2 M sodium phosphate

2H+ + PO43- H2PO4

-

Acid/Base #2 2) Anhydrides mixed in water

i) Base AnhydridesSolid sodium oxide is sprinkled in water

Na2O + H2O 2 Na+ + 2 OH-

(Could also have slightly soluble hydroxides: Ca, Mg)

ii) Acid anhydridesCarbon dioxide gas is bubbled through water

H2O + CO2 H2CO3 H+ + HCO3-

(Remember strong vs. weak acids)

Synthesis and DecompositionAs Anhydride Reaction

1) Decomposition: salt decomposed to acid and and base anhydrides

solid calcium carbonate is heatedCaCO3 CaO + CO2

2) Synthesis: salt synthesized when acid and base anhydrides react

carbon dioxide gas is blown over solid calcium oxide

CaO + CO2 CaCO3

Acid/Base #2: Now You Try

P4O10 + 6H2O 4H3PO4

Solid lithium oxide is sprinkled in water

Solid tetraphosphorous pentoxide is added to water

Li2O + H2O 2Li+ + 2OH-

Iron(II) sulfite is heated strongly

FeSO3 FeO + SO2

Dintrogen pentoxide gas is bubbled through water

N2O5 + H2O 2H+ + 2NO3-

Acid/Base #33) Complex ion Formation (Technically Lewis Acid/Base)

Excess concentrated ammonia is added to solid silver chloride

AgCl + 2 NH3 Ag(NH3)2+ + Cl-

Hints“Excess concentrated”

Ligands we have seen in this class:NH3, 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

Cu2+ + 4NH3 Cu(NH3)42+

Excess concentrated solution of hydrochloric acid is added to solid silver chloride

Excess concentrated ammonia is added to a solution of copper(II) chloride

Co3+ + 6Cl- CoCl63-

AgCl + Cl- AgCl2-

Solid aluminum hydroxide is added to concentrated potassium hydroxide

Al(OH)3 + OH- Al(OH)4-

Final ThoughtsWhen information is given pertaining to reactivity, a reaction ALWAYS occurs.

Use checklist approach to categorize reaction type

Remember unstable acids: H2CO3, H2SO3

and NH4OH

Sulfuric acid appears as either: H+ + HSO4

- (sometimes 2H+ + SO42-)