Types of Reactions There are 5 types of reactions Combination Decomposition Single Displacement Double Displacement Combustion

Combination Reactions Combination reactions have two or more reactants and only one product A + B  AB

Decomposition Reactions Decomposition reactions have only one reactant which breaks down into two or more products AB  A + B

Single Displacement Reactions In a single displacement reaction, an element replaces the atoms of a second element in a compound AB + D  AD + B AB + C  CB + A

Double Displacement Reactions Remember, these involve the exchange of positive ions (or negative ions) between two compounds AB + CD  AD + CB

Combustion When an organic compounds reacts with oxygen to produce water and either CO or CO2 Complete combustion always ends with CO2 and H2O Incomplete combustion always ends with CO and H2O

Combination Reactions When two nonmetals react, or a transition metal reacts with a nonmetal, more than one product is often possible With two nonmetals it is hard to predict the product With the transition metal reacts it depends on the charge being used

Combination Reactions Example Fe(s) + S(s)  Fe(s) + S(s)  FeS(s) iron (II) sulfide Fe(s) + S(s)  Fe2S3(s) iron (III) sulfide Make sure to balance when finished

Combination Reactions When a metal from one of the first two groups reacts with a nonmetal there is only one possible product Use the oxidation number (charge) to determine the final compound

Combination Reactions Example K(s) + Cl2(g)  K+ and Cl-1 so KCl K(s) + Cl2(g)  KCl(s) Make sure to balance

Decomposition Reactions Remember, a decomposition reaction has only one reactant which breaks down into two or more products AB  A + B

Decomposition Reactions The difficulty with decomposition reactions is the products can be any combination of elements or compounds found in the reactant It is usually very difficult to predict decomposition products

Decomposition Reactions Example H2O H2O  H2 + O2 Don’t forget to balance!

Decomposition Reactions Example Mercury (II) oxide(s) HgO  HgO  Hg + O2(g) Don’t forget to balance!

Single Displacement Reactions Remember, a single displacement reaction is when an element replaces the atoms of a second element in a compound AB + D  AD + B AB + C  CB + A

Single Displacement Reactions When a metal replaces another metal in a compound a new compound is formed When forming a new compound, make sure the charges cancel out in the new compound

Single Displacement Reactions “Single Switch” Example Mg + Zn(NO3)2  Mg+2 and NO3-1 so it forms Mg(NO3)2 Mg + Zn(NO3)2  Zn + Mg(NO3)2 Make sure to balance!

Double Displacement Reactions “Double Switch” Remember, these involve the exchange of metals (positive ions) and nonmetals (negative ions) between two compounds AB + CD  AD + CB

Double Displacement Reactions Example BaCl2 + K2CO3  First identify the ions before swaping Ba+2 Cl- K+ CO3-2 BaCl2 + K2CO3  BaCO3 + KCl Don’t forget to balance

Combustion When an organic compounds reacts with oxygen to produce water and either CO or CO2 Complete combustion always ends with CO2 and H2O