Chemical Reactions

Chemical reaction Format Generic Format A + B C + D Reactants Products Substances being mixed LHS of arrow Substance being made RHS of arrow “Yield” = reaction taking place

Types of Chemical Reactions There are five basic types of chemical reactions: Synthesis Decomposition Single Replacement Double Replacement Combustion Five Major Classes of Reactions

Synthesis Synthesis means “to make” Always makes 1 product Fe2O3 Fe Generic RXN A + B C Always makes 1 product Real Life reaction Fe2O3 Fe + O2 Iron (III) Oxide AKA RUST Iron main component in steel Oxygen

Synthesis Reactions Synthesis reactions happen when two or more substances combine to form one compound. 2 Na + Cl2  2 NaCl Al + P  AlP

Synthesis

Synthesis

Magnesium and oxygen Magnesium and Oxygen (shorter) Iron and Sulfur Zinc and Iodine

Decomposition Only 1 Reactant Generic Reaction A B + C Real Life Reaction H2O2 H2 + O2 Hydrogen Peroxide

Decomposition Reactions Decomposition Reactions happen when one substance breaks down into two or more simpler substances. CaF2  Ca + F2 2 Fe2O3  4 Fe + 3 O2

Decomposition

Decomposition

Hydrogen Peroxide decomposition Simple Elephant Toothpaste Old foamy (Elephant Toothpaste!) Sad Gummy Bear Decomposition of Potassium Chlorate and Sugar (at 1:22)

Synthesis and Decomposition Summary

Single Displacement Generic Reaction A + XY X + AY A + XY Y + XA Metal for a metal A + XY X + AY OR A + XY Y + XA Non-metal for a Non-metal

Single Displacement A + XY X + AY Always a Single Element Always a Compound (2 or more elements)

Single Displacement Al + HCl H2 + AlCl3 Single Element Compound (2 or more elements)

Single Replacement Reactions Single Replacement reactions happen when one element is replaced by another in a compound A + BC  AC + B Zn + CuCl  ZnCl + Cu MgO + Ca  Mg + CaO

Single Displacement

Copper (II) Chloride and Aluminum AND Copper (II) Chloride and Magnesium Zinc and Hydrochloric acid Exploding Egg

Double Displacement XB + AY AB + XY 2 Compounds Generic Reaction XB + AY AB + XY 2 Compounds (2 or more elements bonded together)

Double displacement KI + Pb(NO3)2 PbI2 + KNO3 Compound 1 Compound 2 K and Pb switch

Double Replacement Reactions Double Replacement reactions happen when two elements in a reaction exchange places with each other. AB + CD  AD + CB PbCl + KBr  PbBr + KCl HCl+Ca(OH)2H(OH)+CaCl2

Double Displacement

Lead Nitrate and Potassium Iodide Precipitation Reactions

EXCEPTION!!!! Incomplete combustion… your job to look this one up! Burning a substance in the presence of oxygen (O2) Generic reaction CxHy + O2 CO2 + H2O Hydrocarbon ALWAYS EXCEPTION!!!! Incomplete combustion… your job to look this one up!

Combustion CO2 + H2O CO2 + H2O C8H18 + O2 Gasoline CH3OH + O2 Octane Methanol

Combustion Reactions Combustion Reactions involve the burning (O2) of a hydrocarbon to form carbon dioxide and water. CXHY + O2  CO2 + H2O 2C2H6+7O24CO2 + 6H2O 2CH4 + 4O2  2CO2 + 4H2O

Combustion of Alcohols Fire It Up Reactions Methane Bubbles Budapest Combustion (long) Plasma Bottle with Ethyl Alcohol

Water Forming (Neutralization) Carbon Snake Sugar and Sulfuric Acid