TYPES OF Reactions

Reactions can be categorized on the Reactions can be categorized on the basis of:basis of:

1.1. Heat changes- exothermic/ Heat changes- exothermic/ endothermicendothermic

2.2. Reactants and products- 5 typesReactants and products- 5 types

3.3. Reduction and oxidation (REDOX)- Reduction and oxidation (REDOX)- transfer of electrons.transfer of electrons.

Types of ReactionsTypes of Reactions

• There are five types of chemical reactions we will talk about:

1. Synthesis reactions2. _____________ reactions3. Single displacement reactions4. ________________ reactions5. Combustion reactions

• You need to be able to identify the type of reaction and predict the product(s)

Steps to Writing ReactionsSteps to Writing Reactions• Some steps for doing reactions

1. Identify the type of reaction2. Predict the product(s) using the type of

reaction as a model3. Balance it

Don’t forget about the diatomic elements! (BrINClHOF) For example, Oxygen is O2 as an element.

In a compound, it can’t be a diatomic element because it’s not an element anymore, it’s a compound!

1. Synthesis reactions1. Synthesis reactions• Synthesis reactions occur when two

substances (generally elements) combine and form a compound. (Sometimes these are called combination or addition reactions.)

reactant + reactant 1 product• Basically: A + B AB

• Example: 2H2 + O2 2H2O

• Example: C + O2 CO2

Synthesis ReactionsSynthesis Reactions

• Here is another example of a synthesis reaction

PracticePractice

• Predict the products. Write and balance the following synthesis reaction equations.

• Sodium metal reacts with chlorine gas Na(s) + Cl2(g) • Solid Magnesium reacts with fluorine gas Mg(s) + F2(g) • Aluminum metal reacts with fluorine gas Al(s) + F2(g)

2. Decomposition Reactions2. Decomposition Reactions• Decomposition reactions occur

when a compound breaks up into the elements or in a few to simpler compounds

• 1 Reactant Product + Product • In general: AB A + B• Example: 2 H2O 2H2 + O2

• Example: 2 HgO 2Hg + O2

Decomposition ReactionsDecomposition Reactions

• Another view of a decomposition reaction:

Decomposition ExceptionsDecomposition Exceptions

• Carbonates and chlorates are special case decomposition reactions that do not go to the elements.• Carbonates (CO3

2-) decompose to carbon dioxide and a metal oxide

• Example: CaCO3 CO2 + CaO• Chlorates (ClO3

-) decompose to oxygen gas and a metal chloride

• Example: 2 Al(ClO3)3 2 AlCl3 + 9 O2

• There are other special cases, but we will not explore those in Chemistry I

PracticePractice

• Predict the products. Then, write and balance the following decomposition reaction equations:

• Solid Lead (IV) oxide decomposes PbO2(s)

• Aluminum nitride decomposes AlN(s)

PracticePractice

Identify the type of reaction for each of the following synthesis or decomposition reactions, and write the balanced equation:

N2(g) + O2(g)

BaCO3(s)

Co(s)+ S(s)

NH3(g) + H2CO3(aq) (NH4)2CO3

NI3(s) N2 +I2

(Co is +3)

Nitrogen monoxide

Practice p 292Practice p 292

Aluminum oxide decomposes when Aluminum oxide decomposes when electricity passes through it.electricity passes through it.

Nickel (II) hydroxide decomposes to Nickel (II) hydroxide decomposes to produce nickel (II) oxide and water.produce nickel (II) oxide and water.

Heating sodium hydrogen carbonate Heating sodium hydrogen carbonate produces sodium carbonate and produces sodium carbonate and water. Carbon dioxide gas is also water. Carbon dioxide gas is also produced. produced.

3. Single Replacement Reactions3. Single Replacement Reactions• Single Replacement Reactions occur

when one element replaces another in a compound.

• A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-).

• element + compound product + product A + BC AC + B (if A is a metal) ORA + BC BA + C (if A is a nonmetal)

(remember the cation always goes first!)

When H2O splits into ions, it splits intoH+ and OH- (not H+ and O-2 !!)

A more reactive metal will replace a A more reactive metal will replace a less reactive metal from a less reactive metal from a compound. The Activity series of compound. The Activity series of metals lists metals in order of metals lists metals in order of reactivity (p 293) and helps decide reactivity (p 293) and helps decide whether or not the reaction will whether or not the reaction will occur.occur.

Single Replacement ReactionsSingle Replacement Reactions

• Another view:

Activity series of metalsActivity series of metals

lithium, potassium, strontium, calciumlithium, potassium, strontium, calciumsodium , magnesium, aluminumsodium , magnesium, aluminum zinc, chromium ,iron, cadmiumzinc, chromium ,iron, cadmium cobalt, nickel, tin, lead cobalt, nickel, tin, lead HYDROGENHYDROGEN antimony, arsenic, bismuth, copper antimony, arsenic, bismuth, copper mercurymercury Silver, paladiumSilver, paladiumplatinumplatinumgold gold

Single Replacement ReactionsSingle Replacement Reactions

• Write and balance the following single replacement reaction equation:

• Zinc metal reacts with aqueous hydrochloric acid

Zn(s) + HCl(aq) ZnCl2 + H2(g)

Note: Zinc replaces the hydrogen ion in the reaction

2

Single Replacement ReactionsSingle Replacement Reactions• Sodium chloride solid reacts with fluorine gas NaCl(s) + F2(g) NaF(s) + Cl2(g)

Note that fluorine replaces chlorine in the compound

• Aluminum metal reacts with aqueous copper (II) nitrate

Al(s)+ Cu(NO3)2(aq)

2 2

Practice p 295Practice p 295

Predict whether the following Predict whether the following reactions will occur. If a reaction reactions will occur. If a reaction occurs, write a balanced equation for occurs, write a balanced equation for the reaction.the reaction.

K(s)+ZnClK(s)+ZnCl22(aq)-->(aq)--> ClCl22(g)+HF(aq)-->(g)+HF(aq)--> Fe(s)+NaFe(s)+Na33POPO44(aq)-->(aq)--> Al(s)+Pb(NOAl(s)+Pb(NO33))22(aq)-->(aq)-->

4. Double Replacement Reactions4. Double Replacement Reactions

• Double Replacement Reactions occur when a metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound

• Compound + compound product + product (insoluble product= precipitate)

• AB + CD AD + CB

Double Replacement ReactionsDouble Replacement Reactions

First and last ions go together + inside ions go together

• Example: AgNO3(aq) + NaCl(s) AgCl(s) + NaNO3(aq)

• Another example:K2SO4(aq) + Ba(NO3)2(aq) KNO3(aq) + BaSO4(s)

2

PracticePractice

• Predict the products. Balance the equation

n HCl(aq) + AgNO3(aq)

n CaCl2(aq) + Na3PO4(aq) n Pb(NO3)2(aq) + BaCl2(aq) n FeCl3(aq) + NaOH(aq) n H2SO4(aq) + NaOH(aq)

n KOH(aq) + CuSO4(aq)

5. Combustion Reactions5. Combustion Reactions

• Combustion reactions occur when a hydrocarbon reacts with oxygen gas.

• This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”:1) A Fuel (hydrocarbon)2) Oxygen to burn it with3) Something to ignite the reaction (spark)

Combustion ReactionsCombustion Reactions• In general:

CxHy + O2 CO2 + H2O• Products in combustion are

ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide)

• Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C8H18)

Combustion Combustion ReactionsReactions

Edgar Allen Poe’s drooping eyes and mouth are potential signs of CO poisoning.

CombustionCombustion

• Example• C5H12 + O2 CO2 + H2O

• Write the products and balance the following combustion reaction:• C10H22 + O2

5 68

Mixed PracticeMixed Practice

• State the type, predict the products, and balance the following reactions:

1. BaCl2 + H2SO4

2. C6H12 + O2

3. Zn + CuSO4

4. Cs + Br2

5. FeCO3

TYPES OF REACTIONS review 1. NAME THE 5 TYPES OF REACTIONS

AND GIVE AN EXAMPLE OF EACH. (10 pts) 2. CATEGORIZE THE FOLLOWING BASED

ON REACTION TYPE:(5 pts) A). 2H2 +O2 ---2H2 O B). Cl2 +NaI--2NaCl +I2 C). CH4 +2O2 --CO2 +2H2O D).Ca (OH)2 ---CaO + H2O E). NaOH + KCl KOH + NaCl

3. WHICH CONDITION HAS TO BE FULFILLED IN ORDER FOR A SINGLE DISPLACEMENT REACTION TO OCCUR?(1 pt)

4. NAME THE TWO COMMON PRODUCTS OF COMBUSTION REACTIONS.(1 pt)

5. Fill in the blanks with the correct products of this reaction, and balance the equation:(2pts)

PbCl2 + Na2SO4 --> ____ + _______

Acids + BasesAcids + Bases

Acids all contain HAcids all contain H++ cations and an anion. cations and an anion. Bases all contain OHBases all contain OH-- anions and a cation, anions and a cation,

except for weak bases such as NHexcept for weak bases such as NH33

When acids dissociate in water they When acids dissociate in water they release Hrelease H++ ions and their anions. ions and their anions.

When bases dissociate in water they When bases dissociate in water they release or form OHrelease or form OH-- ions and their cations. ions and their cations.

Neutralization ReactionsNeutralization Reactions In the reaction of an acid with a base, the In the reaction of an acid with a base, the

HH++ from the acid combines with the OH from the acid combines with the OH-- from the base to make waterfrom the base to make water

The cation from the base combines with The cation from the base combines with the anion from the acid to make the saltthe anion from the acid to make the salt

acid + base acid + base salt + watersalt + waterHH22SOSO44(aq) + Ca(OH)(aq) + Ca(OH)22(aq) (aq) CaSO CaSO44(aq) + 2 H(aq) + 2 H22O(O(ll))

The net ionic equation for a strong acid-The net ionic equation for a strong acid-strong base reaction is alwaysstrong base reaction is always

HH+ + (aq) + OH(aq) + OH- - (aq) (aq) H H22O(l)O(l)

Neutralization practiceNeutralization practice

P 195 Q 39- Complete and balance P 195 Q 39- Complete and balance the following neutralization the following neutralization reactions. Underline the salt - reactions. Underline the salt -

A. HCl + KOH-->A. HCl + KOH--> RbOH + HNORbOH + HNO33 --> --> HClOHClO44+NaOH-->+NaOH--> HBr+CsOH-->HBr+CsOH-->

Reactions of Metals withReactions of Metals withNonmetals (Oxidation-Reduction)Nonmetals (Oxidation-Reduction)

The metal loses electrons and The metal loses electrons and becomes a cation (becomes a cation (oxidation)oxidation)

The nonmetal gains electrons and The nonmetal gains electrons and becomes an anion (becomes an anion (reduction)reduction)

In the reaction, electrons are In the reaction, electrons are transferred from the metal to the transferred from the metal to the nonmetalnonmetal

Oxidation-Reduction ReactionsOxidation-Reduction Reactions

Oxidation-reduction reactions:Oxidation-reduction reactions: reactions that involve a transfer of reactions that involve a transfer of one or more electronsone or more electrons

The substance that loses electrons in The substance that loses electrons in the reaction is the reaction is oxidizedoxidized. The . The substance that gains electrons in the substance that gains electrons in the reaction is reaction is reduced.reduced.

Another Kind ofAnother Kind ofOxidation-Reduction ReactionOxidation-Reduction Reaction

Some reactions between two non-Some reactions between two non-metals are also oxidation-reduction metals are also oxidation-reduction reaction.reaction.

Any reaction in which OAny reaction in which O22 is a reactant is a reactant or a product will be an oxidation-or a product will be an oxidation-reduction reaction.reduction reaction.

CHCH44(g) + 2 O(g) + 2 O22(g) (g) CO CO22(g) + 2 H(g) + 2 H22O(g)O(g)

2 SO2 SO33(g) (g) 2 SO 2 SO22(g) + O(g) + O22(g)(g)

Self check p 183Self check p 183 For each reaction, show how electrons are For each reaction, show how electrons are

gained and lost.gained and lost. A. 2Na(s)+ BrA. 2Na(s)+ Br22(l)--> 2NaBr(s)(l)--> 2NaBr(s) B. 2Ca(s)+ OB. 2Ca(s)+ O22(g)--> 2CaO(s)(g)--> 2CaO(s) P 196 Q 49- Balance each redox reaction. In P 196 Q 49- Balance each redox reaction. In

each, indicate which substance is being each, indicate which substance is being oxidized and which is being reduced- oxidized and which is being reduced-

A. Na + S--> NaA. Na + S--> Na22SS B. Mg +OB. Mg +O22-->MgO-->MgO C. Ca +FC. Ca +F22--> CaF--> CaF22

Fe +ClFe +Cl22-->FeCl-->FeCl33

Total Ionic EquationsTotal Ionic Equations

Once you write the molecular equation Once you write the molecular equation (synthesis, decomposition, etc.), you should (synthesis, decomposition, etc.), you should check for reactants and products that are check for reactants and products that are soluble or insoluble.soluble or insoluble.

We usually assume the reaction is in waterWe usually assume the reaction is in water We can use a solubility table to tell us which We can use a solubility table to tell us which

compounds dissolve in water.compounds dissolve in water. If the compound is soluble (does dissolve in If the compound is soluble (does dissolve in

water), then split the compound into its water), then split the compound into its component ionscomponent ions

If the compound is insoluble (does NOT If the compound is insoluble (does NOT dissolve in water), then it remains as a dissolve in water), then it remains as a compoundcompound

Solubility TableSolubility Table

Solubilities Not on the Table!Solubilities Not on the Table!

Gases only slightly dissolve in waterGases only slightly dissolve in water Strong acids and bases dissolve in waterStrong acids and bases dissolve in water

Hydrochloric, Hydrobromic, Hydroiodic, Nitric, Hydrochloric, Hydrobromic, Hydroiodic, Nitric, Sulfuric, Perchloric AcidsSulfuric, Perchloric Acids

Group I hydroxides (should be on your chart Group I hydroxides (should be on your chart anyway)anyway)

Water slightly dissolves in water! (H+ and Water slightly dissolves in water! (H+ and OH-)OH-)

SrSOSrSO44 is insoluble; BeI is insoluble; BeI22 and the products are and the products are solublesoluble

There are other tables and rules that cover There are other tables and rules that cover more compounds than your table!more compounds than your table!

Self check p 175Self check p 175

Predict whether a solid will form Predict whether a solid will form when the following parts of solutions when the following parts of solutions are mixed. If so, identify the solid are mixed. If so, identify the solid and write the balanced equation for and write the balanced equation for the reaction-the reaction-

Ba(NOBa(NO33))22(aq) and NaCl(aq)(aq) and NaCl(aq) NaNa22S(aq) and Cu(NOS(aq) and Cu(NO33))22(aq)(aq) NHNH44Cl(aq) and Pb(NOCl(aq) and Pb(NO33))22(aq)(aq)

Total Ionic EquationsTotal Ionic Equations

Molecular Equation:Molecular Equation:

KK22CrOCrO44 + Pb(NO + Pb(NO33))22 PbCrOPbCrO44 + 2 KNO + 2 KNO33

SolubleSoluble SolubleSoluble Insoluble Insoluble Soluble Soluble

Total Ionic Equation:Total Ionic Equation:

2 K2 K++ + CrO + CrO44 -2-2 + Pb + Pb+2+2 + 2 NO + 2 NO33--

PbCrOPbCrO44 (s) + 2 K (s) + 2 K++ + 2 NO + 2 NO33--

Net Ionic EquationsNet Ionic Equations

These are the same as total ionic These are the same as total ionic equations, but you should cancel out ions equations, but you should cancel out ions that appear on BOTH sides of the equation that appear on BOTH sides of the equation (termed as spectator ions)(termed as spectator ions)

Total Ionic Equation(complete):Total Ionic Equation(complete):

2 K2 K++ + CrO + CrO44 -2-2 + Pb + Pb+2+2 + 2 NO + 2 NO33--

PbCrOPbCrO44 (s) + 2 K (s) + 2 K++ + 2 NO + 2 NO33--

Net Ionic Equation:Net Ionic Equation:

CrOCrO44 -2-2 + Pb + Pb+2+2 PbCrO PbCrO44 (s) (s)

Net Ionic EquationsNet Ionic Equations

Try this one! Write the molecular, total ionic, and Try this one! Write the molecular, total ionic, and net ionic equations for this reaction: Silver nitrate net ionic equations for this reaction: Silver nitrate reacts with Lead (II) Chloride in hot water.reacts with Lead (II) Chloride in hot water.

Molecular: Molecular:

Total Ionic:Total Ionic:

Net Ionic:Net Ionic:

Self check p 177Self check p 177

For each of the following reactions, write For each of the following reactions, write the molecular equation, the complete ionic the molecular equation, the complete ionic equation, and the net ionic equation.equation, and the net ionic equation.

Aqueous sodium sulfide is mixed with Aqueous sodium sulfide is mixed with aqueous copper (II) nitrate to produce aqueous copper (II) nitrate to produce solid copper (II) sulfide and aqueous solid copper (II) sulfide and aqueous sodium nitrate.sodium nitrate.

Aqueous ammonium chloride and aqueous Aqueous ammonium chloride and aqueous lead (II) nitrate react to form lead (II) lead (II) nitrate react to form lead (II) chloride and aqueous ammonium nitrate.chloride and aqueous ammonium nitrate.

Study guide for balancing Study guide for balancing equations- Chapter 6equations- Chapter 6

Basic structure of equations- Basic structure of equations- reactants, products, arrow, physical reactants, products, arrow, physical state.state.

Signs of a chemical change.Signs of a chemical change. Law of conservation of matter.Law of conservation of matter. Rules for balancing equations.Rules for balancing equations. Balancing equations.Balancing equations.

Study guide for Types of Study guide for Types of reactions and net ionic reactions and net ionic equations- Chapter 7equations- Chapter 7

types of reactions- definitions, types of reactions- definitions, examples, identification – synthesis, examples, identification – synthesis, decomposition, single and double decomposition, single and double displacement, combustion, displacement, combustion, neutralization and redox!neutralization and redox!

net ionic equations- solubility, net ionic equations- solubility, cancelling ions, spectator ionscancelling ions, spectator ions