Chemical Reactions Quantitative Chem. Indicators of a Chemical Reaction

Chemical Chemical ReactionsReactions

Quantitative Quantitative ChemChem

Indicators of a Chemical Indicators of a Chemical ReactionReaction


1.1. Formation of a Formation of a solidsolid (called a (called a

precipitateprecipitate))


1.1. Formation of a solid Formation of a solid (called a (called a

precipitateprecipitate))2.2. Production of Production of gasgas


1.1. Formation of a solid Formation of a solid (called a (called a

precipitateprecipitate))2.2. Production of gasProduction of gas3.3. Production (or Production (or

absorption) of absorption) of heat and heat and lightlight

Parts of a Chemical Parts of a Chemical EquationEquation

2Na2Na((ss)) + Cl + Cl2 (2 (gg)) 2 NaCl 2 NaCl((ss))



ReactantsReactants Products Products




Coefficients Coefficients




Subscripts Subscripts


2Na2Na((ss)) + Cl + Cl2 (2 (gg)) 2 NaCl 2 NaCl((ss))……...…..……….....…

States of Matter States of Matter

Parts of a Chemical Parts of a Chemical EquationEquationStates of Matter:States of Matter:((ss) = solid) = solid ((ll) = liquid) = liquid((gg) = gas) = gas ((aqaq) = solution) = solutionArrows: Arrows: means “to yield” means “to yield”

or “produce” or “produce”

Why do we need to balance Why do we need to balance a chemical equation?a chemical equation?

Because matter is not created Because matter is not created or destroyed in a chemical or destroyed in a chemical reaction! (The law of reaction! (The law of conservation of matter)conservation of matter)The amount of each element The amount of each element remains the same.remains the same.

Determine the number of Determine the number of atoms in each of the atoms in each of the

following compounds.following compounds.NaCl:NaCl: _____ Na _____ Na _____ Cl_____ ClKK33N:N: _____ K_____ K _____ N_____ NAlAl22OO33:: _____ Al_____ Al __________ OO

Coefficients!Coefficients!

3NaCl:3NaCl: _____ Na _____ Na _____ Cl_____ Cl4Al4Al22OO33:: _____ Al_____ Al __________ OO

Rules for Balancing (Coeff)Rules for Balancing (Coeff)1.1. Start with the most Start with the most complexcomplex

element or compound.element or compound.2.2. Balance Balance oxygenoxygen last last3.3. Balance Balance hydrogenhydrogen second to second to

lastlast4.4. If stuck on oxygen, If stuck on oxygen, doubledouble

everything except Oeverything except O22, then , then balance.balance.

5.5. Double-check your work.Double-check your work.

3. Classifying Reactions and Predicting Products

Examples of Chemical Reactions

• C3H8 + O2 → CO2 + H2O

• NaOH → Na2O + H2O

• H2 + O2 → H2O

• Zn + 2 HCl → H2 + ZnCl2

• K2CrO4 + Pb(NO3)2 →

2 KNO3 + PbCrO4

• H2CrO4 + Pb(OH)2 →

2 H2O + PbCrO4

COMBUSTION

What are some examples?What is it? (write the definition)Reaction 1: Candle Experiment

2C24H50 + 73O2 48CO2 + 50H2O

Reaction 2:CH4 + 2O2 CO2 + 2H2O

Reaction 3:C3H8 + O2 .

What are the characteristics of the reactants that undergo this type of reaction?


What are the products of this type of reaction? (on pg 12)

An exothermic reaction that takes place between a substance and oxygen.

CXHY + O2 CO2 + 2H2O

(X and Y are integers)

A carbon-based substance that reacts with oxygen.

Produces carbon dioxide and water.

C3H8 + O2 CO2 + H2O

EQ?EQ?

C3H8 + 5O2 3CO2 + 4H2O

SYNTHESIS

What are some examples?What is it? (write the definition)Reaction 1: Magnesium + Oxygen

Δ2Mg + O2 2MgO

Reaction 2: Formation of Iron (II) Sulfide Δ8Fe + S8 8FeS

Reaction 3: Formation of Water Δ H2 + O2 .




Two or more reactants combine to form a single product.

A + B AB

Picture

Energy (“Δ”) needs to be supplied.

Only 1 compound is formed

H2 + O2 H2O

EQ?EQ?

2H2 + O2 2H2O

DECOMPOSITION

What are some examples?What is it? (write the definition)Reaction 1: Carbonation in Soda

H2CO3 H2O + CO2

Reaction 2: Decomposition of Water2H2O 2H2 + O2

Reaction 3: Decomposition of Table SaltNaClO3 .




A compound is broken down into two or more simpler substances.

AB A + B

Picture

1. Metallic Hydroxide 2. Metallic Carbonate

3. Metallic Chlorate 4. Oxyacid

5. Binary Compound

Metallic Oxide + H2O Metallic Oxide + CO2

Metallic Chloride + O2

Nonmetallic Oxide + H2O2 Elements

NaClO3 NaCl + O2

EQ?EQ?

2NaClO3 2NaCl + 3O2

SINGLEDISPLACEMENT

What are some examples?What is it? (write the definition)Reaction 1: Copper & Silver Nitrate

Cu + AgNO3 2Ag + Cu(NO3)2

Reaction 2:2NaBr + Cl2 NaCl2 + Br2

Reaction 3:Zn + HCl H2 + ZnCl2




One element displaces another element from a compound.

AX + Z AZ + XA + BX B + AX

A cation replaces a cationAn anion replaces an anion

An element and compound

Zn + HCl H2 + ZnCl2

EQ?EQ?

Zn + 2HCl H2 + ZnCl2

DOUBLEDISPLACEMENT

What are some examples?What is it? (write the definition)Reaction 1: Potassium Iodide + Plumbous Chromate

KI + PbCrO4 K2CrO4 + PbI2

Reaction 2:AgNO3 + CuCl2 AgCl2 + Cu(NO3)

Reaction 3:Fe2(SO4)3 + HCl




Two aqueous compounds switch their cations (or anions).

AC + BD BC + AD Two soluble compounds react

Forms two compounds where the cations (or anions) switch places.

H2SO4 + FeCl3

EQ?EQ?

NEUTRALIZATION

What are some examples?What is it? (write the definition)Reaction 1: Hydrochloric Acid & Sodium Hydroxide

HCl + NaOH NaCl + H2O

Reaction 2:H2SO4 + NaOH Na2SO4 + H2O

Reaction 3:H2CO3 + Ca(OH)2




An acid reacts with a base to form salt and water.

HA + BOH BA + H2O An acid reacts with a hydroxide compound

An ionic compound (“salt”) and water

CaCO3 + H2O

EQ?EQ?

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Chemical Reactions Quantitative Chem. Indicators of a Chemical Reaction