introduction to chemical reactions
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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) + O2 (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:
O2 – flame gets bigger and splint will relight
CO2 – flame will go out
H2 – popping noise (flame may go out from mini explosion!)
• 2 H2O2 (aq) O2 (g) + 2 H2O (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
• (NH4)2Cr2O7 (s) N2 (g) + Cr2O3 (s) + 4 H2O (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) + AgNO3 (aq) Ag(s) + CuNO3 (aq) (blue)
• Iron nail + copper (II) chloride solution solid copper + iron (II) chloride solution
• Fe(s) + CuCl2 (aq) FeCl2 (aq) + Cu (s) (red)
• Solid zinc + aqueous hydrochloric acid hydrogen gas + aqueous zinc chloride
• Zn(s) + 2HCl(aq) ZnCl2 (aq) + H2 (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
• 3Cl2 (g) + 2AlBr3 (aq) 3Br2 (g) + 2AlCl3 (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 (NO3)2 (aq) + 2 NaOH (aq) Cu (OH)2 (s) + 2 NaNO3 (aq)
• aqueous silver nitrate + potassium chromate aqueous potassium nitrate + solid silver chromate
• AgNO3 (aq) + K2CrO4 (aq) KNO3 (aq) + Ag2CrO4 (s)
• In order for a double replacement reaction to occur, one of the following must be produced:
Gas
Water
Precipitate (ppt.)
Precipitation Animation
• http://www.mhhe.com/physsci/chemistry/animations/chang_7e_esp/crm3s2_3.swf
Combustion
• Hydrocarbon + oxygen carbon dioxide + water + heat
• Hydrocarbon is a compound containing carbon, hydrogen and sometimes oxygen (CxHyOz)
• aqueous methanol + oxygen gas carbon dioxide gas + liquid water
• 2 CH3OH(aq) + 3 O2 (g) 2 CO2 (g) +
4 H2O (l) + heat
• methane gas + oxygen gas carbon dioxide gas + water vapor
• CH4 (g) + 2O2 (g) CO2 (g) + 2H2O(g)