Chemical Chemical ReactionsReactions

ObjectivesObjectives

1) Write and balance equations1) Write and balance equations 2) Identifying the types of reactions2) Identifying the types of reactions

Reactants and ProductsReactants and Products

Gallium + Sulfuric acid → Gallium Sulfate + Gallium + Sulfuric acid → Gallium Sulfate + HydrogenHydrogen

Reactants- left side of the arrowReactants- left side of the arrow

-starting materials-starting materials Products-right side of the arrowProducts-right side of the arrow

-the substance made, produced-the substance made, produced The number of atoms on the reactant side The number of atoms on the reactant side

must equal the number of atoms on the must equal the number of atoms on the product side.product side.

BalancingBalancing

Rules:Rules: 1) Write the correct chemical formula for the 1) Write the correct chemical formula for the

reactants and the products.reactants and the products. 2) Adjust the coefficients (the numbers that 2) Adjust the coefficients (the numbers that

appear in front of the formulas) only and evenly.appear in front of the formulas) only and evenly. 3) Never change the subscripts (the small 3) Never change the subscripts (the small

numbers in a formula)numbers in a formula) 4) When counting atoms, multiply the 4) When counting atoms, multiply the

coefficients by the subscript for each element.coefficients by the subscript for each element. 5) There are seven elements, that when left 5) There are seven elements, that when left

alone, exist as diatomic molecules. alone, exist as diatomic molecules. BrBr22 I I22 N N22 Cl Cl22 HH22 OO22 FF22

Balancing ExampleBalancing Example

Ga + HGa + H22SOSO44 → Ga → Ga22(SO(SO44))33 + H + H22

Balanced:Balanced: 2Ga + 3H2Ga + 3H22SOSO4 4 → Ga → Ga22(SO(SO44))33 + 3H + 3H22

Identifying ReactionsIdentifying Reactions

The five types of reactions:The five types of reactions:

-Synthesis or Combination-Synthesis or Combination

-Single Replacement-Single Replacement

-Double Replacement-Double Replacement

-Combustion-Combustion

-Decomposition (6 types)-Decomposition (6 types)

SynthesisSynthesis

element + element → compoundelement + element → compound Occurs when two or more elements are Occurs when two or more elements are

combined to form a new substancecombined to form a new substance Also called CombinationAlso called Combination

Synthesis or Synthesis or CombinationCombination

Example:Example:

2 Na + Cl2 Na + Cl22 → 2NaCl → 2NaCl

Jayhawk says: Here’s an example of synthesis:

+ = Rivalry

Single ReplacementSingle Replacement

Occurs when one element displaces another Occurs when one element displaces another in a compound.in a compound.

A + BC → B + ACA + BC → B + ACelement + compound → element + compoundelement + compound → element + compound

Single ReplacementSingle Replacement

Example:Example:

Na + LiCl → NaCl + LiNa + LiCl → NaCl + Li

Listen up ,class, it’s time for an example.

Double ReplacementDouble Replacement

Occurs when the positive and negative ions of the two Occurs when the positive and negative ions of the two reactants are interchangedreactants are interchanged

AB + CD → AD + CBAB + CD → AD + CB compound + compound→compound compound + compound→compound

+compound+compound Never put two metals togetherNever put two metals together

Double ReplacementDouble Replacement

Example:Example:

2NaCl + Li2NaCl + Li22O → NaO → Na22O + 2LiClO + 2LiCl

Did you know? Double replacement is also referred to as metathesis.

CombustionCombustion

Hydrocarbon + OHydrocarbon + O22 → H → H22O + COO + CO22

CombustionCombustion

Example: Example: CC44HH88 + O + O22 →H →H22O + COO + CO22

DecompositionDecomposition Occurs when energy in the form of heat, light, Occurs when energy in the form of heat, light,

electricity, or mechanical shock is supplied. A electricity, or mechanical shock is supplied. A compound may decompose to form simpler compound may decompose to form simpler compounds and/or elements. compounds and/or elements.

compound → 2 or more substancescompound → 2 or more substances→→

DecompositionDecomposition There are 6 different types of decompositionThere are 6 different types of decomposition

Did you know? You might also know decomposition by analysis.

Electrical DecompositionElectrical Decomposition

AB → A + BAB → A + B

2NaCl → 2Na + Cl2NaCl → 2Na + Cl22

Decomposition: Oxy-AcidDecomposition: Oxy-Acid

Oxy-Acid → Water + Nonmetal Oxy-Acid → Water + Nonmetal OxideOxide

HH22SOSO4 4 → H→ H22O + SOO + SO33

Examples:Examples: HNOHNO33

HH33POPO44

HClOHClO22

Decomposition: Metallic Decomposition: Metallic HydroxideHydroxide

Metallic Hydroxide → Metal Oxide Metallic Hydroxide → Metal Oxide + Water+ Water

2LiOH → Li2LiOH → Li22O + HO + H22OO

Fe(OH)Fe(OH)2 2 → FeO + H→ FeO + H22OO

Decomposition: Metallic Decomposition: Metallic CarbonateCarbonate

Metallic Carbonate → Metal Oxide Metallic Carbonate → Metal Oxide +Carbon Dioxide+Carbon Dioxide

MgCOMgCO33 → MgO + CO → MgO + CO22

FeFe22(CO(CO33))22 → Fe → Fe22OO33 + 3CO + 3CO22

Decomposition: Metallic Decomposition: Metallic ChlorateChlorate

Metallic Chlorate → Metal Chloride Metallic Chlorate → Metal Chloride + Oxygen+ Oxygen

2LiClO2LiClO22 → 2LiCl + 3O → 2LiCl + 3O22

Ca(ClOCa(ClO33))22 → CaCl → CaCl22 + 3O + 3O22

Decomposition: Metallic Decomposition: Metallic OxideOxide

Metallic Oxide → Metal + Metallic Oxide → Metal + OxygenOxygen

2Li2Li22O → 4Li + OO → 4Li + O22

2BaO → 2Ba + O2BaO → 2Ba + O22

THETHE ENDEND