Introduction to Chemical Reactions Learning Reaction Types and Their Patterns

Synthesis A + B  AB Element A + Element B  Compound AB Magnesium Strip + Oxygen Gas  Solid Magnesium Oxide

2 Mg (s) + O 2 (g)  2 MgO (s) (white powder)

Decomposition AB  A + B Compound AB  Element A + Element B Aqueous hydrogen peroxide  oxygen gas + liquid water

Splint Test A test used to determine the production of one of the following gases: O 2 – flame gets bigger and splint will relight CO 2 – flame will go out H 2 – popping noise (flame may go out from mini explosion!)

2 H 2 O 2 (aq)  O 2 (g) + 2 H 2 O (l)

ABCD  AB + C + D Compound ABCD  Compound AB + Element C + Element D Solid ammonium dichromate  solid chromium (III) oxide + nitrogen gas + water vapor

ABCD  AB + C + D Compound ABCD  Compound AB + Element C + Element D Solid ammonium dichromate  solid chromium (III) oxide + nitrogen gas + water vapor

(NH 4 ) 2 Cr 2 O 7 (s)  N 2 (g) + Cr 2 O 3 (s) + 4 H 2 O (g)

Single Replacement - Cationic A + BC  B + AC Element A+ Compound BC  Element B+ Compound AC Note: Elements A & B are metals Copper wire + aqueous silver nitrate  solid silver + aqueous copper (I) nitrate

Cu (s) + AgNO 3 (aq)  Ag (s) + CuNO 3 (aq) (blue)

Iron nail + copper (II) chloride solution  solid copper + iron (II) chloride solution

Fe (s) + CuCl 2 (aq)  FeCl 2 (aq) + Cu (s) (red)

Solid zinc + aqueous hydrochloric acid  hydrogen gas + aqueous zinc chloride

Zn (s) + 2HCl (aq)  ZnCl 2 (aq) + H 2 (g) (“pop” splint test)

Single Replacement - Anionic A + BC  C + BA Element A + Compound BC  Element C + Compound BA Note: Elements A & C are nonmetals

Chlorine gas + aluminum bromide solution  bromine gas + aluminum chloride solution

3Cl 2 (g) + 2AlBr 3 (aq)  3Br 2 (g) + 2AlCl 3 (aq)

Double Replacement AB + CD  AD + CB Compound AB + Compound CD  Compound AD + Compound BC aqueous copper (II) nitrate + aqueous sodium hydroxide  copper (II) hydroxide (ppt) + aqueous sodium nitrate.

Cu (NO 3 ) 2 (aq) + 2 NaOH (aq)  Cu (OH) 2 (s) + 2 NaNO 3 (aq)

aqueous silver nitrate + potassium chromate  aqueous potassium nitrate + solid silver chromate

AgNO 3 (aq) + K 2 CrO 4 (aq)  KNO 3 (aq) + Ag 2 CrO 4 (s)

In order for a double replacement reaction to occur, one of the following must be produced: Gas Water Precipitate (ppt.)

Precipitation Animation /animations/chang_7e_esp/crm3s2_3.s wfhttp:// /animations/chang_7e_esp/crm3s2_3.s wf

Combustion Hydrocarbon + oxygen  carbon dioxide + water + heat Hydrocarbon is a compound containing carbon, hydrogen and sometimes oxygen (C x H y O z ) aqueous methanol + oxygen gas  carbon dioxide gas + liquid water

2 CH 3 OH (aq) + 3 O 2 (g)  2 CO 2 (g) + 4 H 2 O (l) + heat

methane gas + oxygen gas  carbon dioxide gas + water vapor

CH 4 (g) + 2O 2 (g)  CO 2 (g) + 2H 2 O (g)