Types of Reactions There are 5 types of

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 CO 2 • Complete combustion always ends with CO 2 and H 2 O • Incomplete combustion always ends with CO and H 2 O

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) iron (II) sulfide – Fe(s) + S(s) Fe 2 S 3(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) + Cl 2(g) K+ and Cl-1 so KCl K(s) + Cl 2(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 – H 2 O H 2 + O 2 – Don’t forget to balance!

Decomposition Reactions • Example – Mercury (II) oxide(s) – Hg. O Hg + O 2(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(NO 3)2 – Mg+2 and NO 3 -1 so it forms Mg(NO 3)2 – Mg + Zn(NO 3)2 Zn + Mg(NO 3)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 – Ba. Cl 2 + K 2 CO 3 – First identify the ions before swaping • Ba+2 Cl- K+ CO 3 -2 – Ba. Cl 2 + K 2 CO 3 Ba. CO 3 + KCl – Don’t forget to balance

Combustion • When an organic compounds reacts with oxygen to produce water and either CO or CO 2 • Complete combustion always ends with CO 2 and H 2 O