WednesdayWednesdayDecember 2, 2009December 2, 2009

(Discussion)(Discussion)

Bell Ringer 12-2-09

Write both the word equation and balanced

formula equation for the following reaction.

Solid zinc (II) sulfide reacts with oxygen gas to produce

solid zinc (II) oxide and gaseous sulfur dioxide.

AnnouncementsAnnouncements Our next test will be

next Tuesday – 12/8.

Assignments Currently OpenAssignments Currently Open

AssignmentAssignment PagePage Date Date IssuedIssued

Date Into Date Into GradeSpeedGradeSpeed

Last Day Last Day to Turn Into Turn In

WS: Intermolecular Forces, Hydrogen Bonding, Metals

173 11/16 11/30 12/2

WS: Building Ionic Compounds

177 11/17 12/1 12/8

WS: Building Molecular Compounds

181 11/19 12/3 12/10

WS: Chemical Reactions and Equations

189 12/1 12/8 12/15

Sample ProblemSample ProblemAluminum sulfate and calcium hydroxide are used Aluminum sulfate and calcium hydroxide are used in a water-purification process. When added to in a water-purification process. When added to water, they dissolve and react to produce two water, they dissolve and react to produce two insoluble products, aluminum hydroxide and insoluble products, aluminum hydroxide and

calcium sulfate. These products settle out, taking calcium sulfate. These products settle out, taking suspended solid impurities with them. Write a suspended solid impurities with them. Write a balanced chemical equation for the reaction.balanced chemical equation for the reaction.

AlAl22(SO(SO44))33 + Ca(OH) + Ca(OH)22 → →

Al(OH)Al(OH)33 + CaSO + CaSO44

3

32

Types of Chemical ReactionsTypes of Chemical Reactions

Synthesis ReactionsSynthesis Reactions

Decomposition ReactionsDecomposition Reactions

Single-Replacement ReactionsSingle-Replacement Reactions

Double-Replacement ReactionsDouble-Replacement Reactions

Combustion ReactionsCombustion Reactions

Synthesis ReactionsSynthesis ReactionsIn In synthesis reactionssynthesis reactions (also called (also called

addition reactions), two or more addition reactions), two or more substances combine to form a new substances combine to form a new

compound.compound.

A + X A + X → AX→ AX

2Mg + O2Mg + O22 → 2MgO → 2MgO

2H2H22 + O + O22 → 2H → 2H22OO

16Rb + S16Rb + S88 → 8Rb → 8Rb22SS

CaO + HCaO + H22O → Ca(OH)O → Ca(OH)22

Decomposition ReactionsDecomposition ReactionsIn a In a decomposition reactiondecomposition reaction, a single , a single compound undergoes a reaction that compound undergoes a reaction that

produces two or more simpler produces two or more simpler substances. substances.

AX AX → A + X→ A + X

2H2H22O → 2HO → 2H22 + O + O22

2HgO → 2Hg + O2HgO → 2Hg + O22

2KClO2KClO33 → 2KCl + 3O → 2KCl + 3O22

Single-Replacement ReactionsSingle-Replacement Reactions

In a In a single-replacement reactionsingle-replacement reaction, one , one element replaces a similar element element replaces a similar element

in a compound. in a compound.

A + BX A + BX → AX + B→ AX + B

Mg + 2HCl → MgClMg + 2HCl → MgCl2 2 + + HH22

ClCl22 + 2KBr → 2KCl + Br + 2KBr → 2KCl + Br22

2Al + 3Pb(NO2Al + 3Pb(NO33))22 → 3Pb + 2Al(NO → 3Pb + 2Al(NO33))33

Double-Replacement ReactionsDouble-Replacement Reactions

In a In a double-replacement reactiondouble-replacement reaction, the , the ions of two compounds exchange ions of two compounds exchange

places in an aqueous solution to form places in an aqueous solution to form two new compounds.two new compounds.

AX + BY AX + BY → AY + BX→ AY + BX

HCl + NaOH → NaCl + HHCl + NaOH → NaCl + H22O O

2KI + Pb(NO2KI + Pb(NO33))22 → PbI → PbI22 + 2KNO + 2KNO33

FeS + 2HCl → HFeS + 2HCl → H22S + FeClS + FeCl22

Combustion ReactionsCombustion ReactionsIn a In a combustion reactioncombustion reaction, a carbon-, a carbon-containing substance combines with containing substance combines with

oxygen to produce carbon dioxide and oxygen to produce carbon dioxide and water, and releasing a large amount water, and releasing a large amount

of energy in the form of light and of energy in the form of light and heat.heat.

CX + OCX + O22 → CO→ CO22 + H + H22OO

CHCH44 + 2O + 2O22 → CO → CO22 + 2H + 2H22OO

CC33HH66 + 5O + 5O22 → 3CO → 3CO22 + 4H + 4H22OO

Activity SeriesActivity Series The ability of an element to react is The ability of an element to react is

called the element’s called the element’s activityactivity.. An An activity seriesactivity series is a list of elements is a list of elements

organized according to the ease with organized according to the ease with which the elements undergo certain which the elements undergo certain chemical reactions.chemical reactions.

For For metalsmetals, greater activity means a , greater activity means a greater ease of loss of electrons, to greater ease of loss of electrons, to form positive ions.form positive ions.

For For nonmetalsnonmetals, greater activity , greater activity means a greater ease of gain of means a greater ease of gain of electrons, to form negative ions.electrons, to form negative ions.

Activity SeriesActivity Series The order in which the elements are listed in an The order in which the elements are listed in an

activity series is usually determined by single- activity series is usually determined by single-replacement reactions.replacement reactions.

The most active element, placed at the top in The most active element, placed at the top in the series, can replace each of the elements the series, can replace each of the elements below it from a compound in a single-below it from a compound in a single-replacement reaction.replacement reaction.

An element farther down can replace any An element farther down can replace any element below it but not any above it.element below it but not any above it.

Activity series are used to help predict whether Activity series are used to help predict whether certain chemical reactions will occur.certain chemical reactions will occur.

Activity SeriesActivity Series See Table 8-3.See Table 8-3.

– Ex) According to the Ex) According to the activity series for activity series for metals, aluminum metals, aluminum replaces zinc.replaces zinc. We, therefore, can We, therefore, can

predict that the predict that the following reaction does following reaction does occur:occur:

2Al + 3ZnCl2 2Al + 3ZnCl2 → 3Zn + → 3Zn + 2AlCl2AlCl33

– Ex) Cobalt cannot Ex) Cobalt cannot replace sodiumreplace sodium We, therefore, can We, therefore, can

predict that the predict that the following reaction following reaction does does not not occur:occur:

Co + 2NaCl Co + 2NaCl → no → no reactionreaction

Activity SeriesActivity SeriesSample ProblemSample Problem

Sn + OSn + O22 → SnO → SnO22

Any metal more active than silver will Any metal more active than silver will react with oxygen to form an oxide.react with oxygen to form an oxide.Tin is above silver in the activity Tin is above silver in the activity

series, therefore a reaction will occur.series, therefore a reaction will occur.The product will be tin oxide,The product will be tin oxide,

either SnO or SnOeither SnO or SnO22

Activity SeriesActivity SeriesSample ProblemSample Problem

Cd + Pb(NOCd + Pb(NO33))22 → Pb + Cd(NO → Pb + Cd(NO33))22

An element will replace any element An element will replace any element below it in the activity series from a below it in the activity series from a

compound in aqueous solution.compound in aqueous solution.

Cadmium is above lead, therefore a Cadmium is above lead, therefore a reaction will occur to produce lead reaction will occur to produce lead

and cadmium nitrate.and cadmium nitrate.

Activity SeriesActivity SeriesSample ProblemSample Problem

Cu + HCl → no reactionCu + HCl → no reactionAny metal more active than hydrogen Any metal more active than hydrogen

will replace hydrogen from an acid.will replace hydrogen from an acid.

Copper is not above hydrogen in the Copper is not above hydrogen in the series, therefore no reaction will series, therefore no reaction will

occur.occur.

Activity SeriesActivity SeriesQuestionQuestion

How is the activity series useful in How is the activity series useful in predicting chemical behavior?predicting chemical behavior?

It helps predict whether a It helps predict whether a chemical reaction will occur and chemical reaction will occur and

what the product(s) of the reaction what the product(s) of the reaction will be.will be.

Activity SeriesActivity SeriesQuestionQuestion

Based on the activity series, Based on the activity series, predict whether the following predict whether the following

reaction will occur?reaction will occur?

Ni + HNi + H22O O → →

NoNo

Activity SeriesActivity SeriesQuestionQuestion

Based on the activity series, Based on the activity series, predict whether the following predict whether the following

reaction will occur?reaction will occur?

BrBr22 + KI + KI →→

2KBr + I2KBr + I22

Activity SeriesActivity SeriesQuestionQuestion

Based on the activity series, Based on the activity series, predict whether the following predict whether the following

reaction will occur?reaction will occur?

Au + HCl Au + HCl →→

NoNo

Activity SeriesActivity SeriesQuestionQuestion

Based on the activity series, Based on the activity series, predict whether the following predict whether the following

reaction will occur?reaction will occur?

Cd + HCl Cd + HCl →→

CdClCdCl22 + H + H22

22

Activity SeriesActivity SeriesQuestionQuestion

Based on the activity series, Based on the activity series, predict whether the following predict whether the following

reaction will occur?reaction will occur?

Mg + Co(NOMg + Co(NO33))22 →→

Mg(NOMg(NO33))22 + Co + Co

Continue WorksheetContinue Worksheet

Chemical Reactions Chemical Reactions and Equationsand Equations

(Page 189)(Page 189)