Properties and Properties and Changes in Matter Changes in Matter

& /Chemical & /Chemical Equations and Equations and

Reactions NotesReactions Notes

Properties and Changes in Properties and Changes in Matter Matter

PropertiesProperties and and ChangesChanges are grouped are grouped intointo 22 general types: general types:

physical propertiesphysical properties and and chemical chemical propertiesproperties; ; physical changesphysical changes and and chemical changeschemical changes..

1.1. Physical propertyPhysical property: a characteristic : a characteristic that can be observed or measured that can be observed or measured without changing the identity of the without changing the identity of the substance. Ex: melting point or substance. Ex: melting point or boiling pointboiling point

2.2. Physical changePhysical change: a change in a : a change in a substance that does not involve a substance that does not involve a change in the identity of the change in the identity of the substance. Ex: cutting, grinding, substance. Ex: cutting, grinding, melting…melting…

Change of State: a physical Change of State: a physical change from one state to change from one state to

another.another.

b. Liquid: definite volume without a definite shape; particles are close together but can move past one another – particles in a liquid move more rapidly than those in a solid.

a. Solid: definite volume and shape; particles are tightly packed together in an ordered fashion and only vibrate about their fixed positions.

c. Gas: neither a definite volume or c. Gas: neither a definite volume or shape; particles are far apart and shape; particles are far apart and move very rapidly.move very rapidly.

d. Plasma: high-temperature physical d. Plasma: high-temperature physical state in which atoms lose their state in which atoms lose their electrons.electrons.

** Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible.

4. 4. Chemical propertyChemical property: a substances’ : a substances’ ability to transform into different ability to transform into different substances. substances.

Ex: ability iron has to rust by combining Ex: ability iron has to rust by combining with the oxygen in air.with the oxygen in air.

5. 5. Chemical changeChemical change or chemical reaction: a or chemical reaction: a change in a substance that involves it changing change in a substance that involves it changing into a different substance. Ex: burning charcoal into a different substance. Ex: burning charcoal (carbon and oxygen) turns it into carbon dioxide.(carbon and oxygen) turns it into carbon dioxide.

A chemical change or reaction is written as an A chemical change or reaction is written as an equation:equation:

(charcoal)(charcoal)Carbon Carbon + + Oxygen Oxygen Carbon DioxideCarbon Dioxide   ReactantsReactants Products Products

Reaction with Reaction with acidsacids

Reaction with Reaction with bases (alkalis)bases (alkalis)

Reaction with Reaction with oxygen oxygen (combustion)(combustion)

Ability to act as Ability to act as oxidizing agentoxidizing agent

Ability to act as Ability to act as reducing agentreducing agent

Reaction with Reaction with other elementsother elements

Decomposition into Decomposition into simpler substancessimpler substances

CorrosionCorrosion

Bubbles of gas Bubbles of gas appearappear

A precipitate formsA precipitate forms AA color color changechange

occursoccurs The temperature The temperature

changeschanges Light is emittedLight is emitted

Indications of a chemical change:

Balancing Balancing Chemical Chemical EquationsEquations

What goes in must come out!What goes in must come out!

Because of the principle of the Because of the principle of the Conservation of MatterConservation of Matter,,

an an equation must be equation must be balancedbalanced..

It must have the same number of It must have the same number of

atoms of the same kind on atoms of the same kind on

both sides.both sides. Lavoisier, 1788Lavoisier, 1788

Chemical EquationsChemical Equations

You need to remember this law!You need to remember this law!

The Law of The Law of Conservation of MassConservation of Mass states: states: that mass is neither created nor that mass is neither created nor destroyed in any chemical reactiondestroyed in any chemical reaction.. Therefore balancing of equations Therefore balancing of equations requires the same number of atoms on requires the same number of atoms on both sides of a chemical reaction. both sides of a chemical reaction.

The number of atoms in the The number of atoms in the ReactantsReactants must equal the number of atoms in the must equal the number of atoms in the ProductsProducts

A properly written chemical equation can A properly written chemical equation can summarize any chemical change. The following summarize any chemical change. The following requirements will help you write and read a requirements will help you write and read a chemical equation:chemical equation:

A. The equation must represent facts. (Chemical A. The equation must represent facts. (Chemical analysis in a laboratory must have been done.)analysis in a laboratory must have been done.)

B. The equation must contain the correct formulas B. The equation must contain the correct formulas for the reactants (on the left of the arrow) and the for the reactants (on the left of the arrow) and the products (on the right of the arrow).products (on the right of the arrow).

C. The Law of Conservation of Mass and Energy C. The Law of Conservation of Mass and Energy must be satisfied.must be satisfied.

Balancing a chemical equation is much like the Balancing a chemical equation is much like the work of an accountant who has to show every work of an accountant who has to show every penny that comes in and where it has gone to.penny that comes in and where it has gone to.

A simple equation, such as A simple equation, such as the synthesis of the synthesis of Iron (II) Iron (II)

sulfidesulfide, , iron + sulfur Iron (II) sulfideiron + sulfur Iron (II) sulfide

Fe + S FeSFe + S FeS

Note that in a chemical equation, we Note that in a chemical equation, we use the arrow “ " instead of the use the arrow “ " instead of the equals “ = ". equals “ = ".

Balancing Balancing Equations EquationsBalancing Balancing Equations Equations

___ Al(s) + ___ Br___ Al(s) + ___ Br22(l) ---> ___ (l) ---> ___ AlAl22BrBr66(s)(s)

2 3

Steps to Balancing a Chemical Steps to Balancing a Chemical EquationEquation

1.1. Write all Write all reactants on the reactants on the left and all left and all products on the products on the right side of the right side of the equation arrow. equation arrow. Make sure you Make sure you write the write the correct formula correct formula for each for each elementelement

2. 2. Use coefficients Use coefficients in front of each in front of each formula to formula to balance the balance the number of atoms number of atoms on each side.on each side.

Steps to Balancing a Chemical Steps to Balancing a Chemical EquationEquation

3. Multiply the 3. Multiply the coefficient of coefficient of each element by each element by the subscript of the subscript of the element to the element to count the count the atoms. Then list atoms. Then list the number of the number of atoms of each atoms of each element on each element on each side. side.

44. It is often easiest to . It is often easiest to start balancing with start balancing with an element that an element that appears only once on appears only once on each side of the arrow. each side of the arrow. These elements must These elements must have the same have the same coefficient. Next coefficient. Next balance elements that balance elements that appear only once on appear only once on each side but have each side but have different numbers of different numbers of atoms. Finally balance atoms. Finally balance elements that are in elements that are in two formulas in the two formulas in the same side. same side.

Re-cap of steps from Re-cap of steps from rule 4:rule 4:

Balance elements that appear only Balance elements that appear only once on each side of the arrow.once on each side of the arrow.

Next balance elements that appear Next balance elements that appear only once on each side but have only once on each side but have different numbers of atoms. different numbers of atoms.

Finally balance elements that are in Finally balance elements that are in two formulas in the same side.two formulas in the same side.

Balancing Balancing Chemical Chemical EquationsEquations

An easier wayAn easier way

(Atomic Inventory)(Atomic Inventory)

First you need an equation with the correct “formula” ………. You’ll probably be given this in the question

Just like this one

Mg + O2 MgO

Then all you do is list the atoms that are involved on each side of the arrow

Mg + O2 MgOMgO

MgO

[1] Just count up the atoms on each side

Then start balancing:

Mg + O2 MgOMg

O

1

1

1

2

[2] The numbers aren’t balanced so then add “BIG” numbers to make up for any shortages

And adjust totals

Mg + O2 MgOMg

O

1

1

1

2

2

2

2

Mg + O2 MgOMg

O

1

2

2

2

2

But the numbers still aren’t equal, so add another “BIG” number

2

And adjust totals again

NOW BOTH SIDES HAVE EQUAL NUMBERS OF ATOMS

WE SAY THAT THE EQUATION IS BALANCED!!

2

Try to balance these equations using the same method:

[1] Na + Cl2 NaCl

[2] CH4 + O2 CO2 + H2O

[4] Al + O2 Al2O3

[3] Li + HNO3 LiNO3 + H2

[1] 2 Na + Cl2 2 NaCl

[2] CH4 + 2 O2 CO2 + 2 H2O

[4] 4 Al + 3 O2 2 Al2O3

[3] 2 Li + 2 HNO3 2 LiNO3 + H2

Here are the answers:

Another example:Another example:

NHNH33 + O + O22 NO + H NO + H22O O

ReactantsReactants ProductsProducts

N appears once on both sides in N appears once on both sides in equal numbers, so the coefficient for equal numbers, so the coefficient for NHNH33 is the same as for NO. is the same as for NO.

Example: Example: NHNH33 + O + O22 NO + H NO + H22OO

Next look at H which appears only Next look at H which appears only once on each side but has different once on each side but has different numbers of atoms, 3 on the left and numbers of atoms, 3 on the left and 2 on the right. The least common 2 on the right. The least common multiple of 3 and 2 is 6, so rewrite multiple of 3 and 2 is 6, so rewrite the equation to get 6 atoms of H on the equation to get 6 atoms of H on both sides:both sides:

22NHNH33 + O + O22 22NO + NO + 33HH22O O

22NHNH33 + O + O2 2 22NO + NO + 33HH22O O

There are 2 oxygen atoms on the left There are 2 oxygen atoms on the left and 5 on the right — the least and 5 on the right — the least common multiple of 2 and 5 is 10, so common multiple of 2 and 5 is 10, so rewrite the equation as: rewrite the equation as:

22NHNH33 + + 55OO22 44NO + NO + 66HH22O O

Now count the atoms on Now count the atoms on each side:each side:

22NHNH33 + + 55OO2 2 44NO + NO + 66HH22OO (Write them out keeping them on the appropriate side of the chemical (Write them out keeping them on the appropriate side of the chemical

equation)equation)

22 N N (nitrogen atoms)(nitrogen atoms) 44 N N (nitrogen (nitrogen atoms)atoms)

66 H H (hydrogen atoms)(hydrogen atoms) 1212 H H (hydrogen atoms)(hydrogen atoms) 1010 O O (oxygen atoms)(oxygen atoms) 1010 O O (oxygen atoms)(oxygen atoms)

This shows the equation not to be balanced This shows the equation not to be balanced “YET”“YET”

Check the number again:Check the number again:

If you double the N and H on the left If you double the N and H on the left the equation will be balanced:the equation will be balanced:

44NH3 + NH3 + 55O2 O2 44NO + NO + 66H2O H2O

Double-check:Double-check:

44NH3 + NH3 + 55O2 O2 44NO + NO + 66H2OH2O

44 N N (nitrogen atoms)(nitrogen atoms) 44 N N (nitrogen (nitrogen atoms)atoms)

1212 H H ((hydrogen atoms)hydrogen atoms) 1212 H H ((hydrogen hydrogen atoms)atoms)

1010 O O (oxygen atoms)(oxygen atoms) 1010 O O ((oxygen oxygen atoms)atoms)

The equation is The equation is Balanced.Balanced.

Balancing hydrocarbons: Balancing hydrocarbons:

Propane + oxygen Propane + oxygen carbon dioxide + carbon dioxide + waterwater

11stst: Write the equation : Write the equation using correct symbols.using correct symbols.

A. Propane – is a hydrocarbon (a combination A. Propane – is a hydrocarbon (a combination of hydrogen and carbon), propane is Cof hydrogen and carbon), propane is C33HH88

B. Oxygen – is a diatomic molecule – in B. Oxygen – is a diatomic molecule – in nature oxygen exists as Onature oxygen exists as O22. In an equation, . In an equation,

if the word oxygen, hydrogen, nitrogen, if the word oxygen, hydrogen, nitrogen, fluorine, chlorine, bromine, iodine, sulfur, or fluorine, chlorine, bromine, iodine, sulfur, or phosphorus is used you must write it as phosphorus is used you must write it as being diatomic (or polyatomic). Remember being diatomic (or polyatomic). Remember HOFBrINCl!HOFBrINCl!

C. Carbon dioxide – binary molecular C. Carbon dioxide – binary molecular compound COcompound CO22..

D. Water – common name for D. Water – common name for dihydrogen monoxide Hdihydrogen monoxide H22O.O.

CC33HH88 + O + O22 CO CO22 + H + H22O O

CC33HH88 + O + O22 CO CO22 + H + H22O O

  

  2nd: Now we must balance the 2nd: Now we must balance the equation – first write an atom inventory equation – first write an atom inventory for the total number of atoms of each for the total number of atoms of each element on each side of the equation.element on each side of the equation.

ReactantsReactants

# C# C 11# H # H 88# O # O 22

ProductsProducts

# C# C 33# H # H 22# O # O 33

___C___C33HH88(g) + _(g) + _55_O_O22 _ _33_CO_CO22 + + 44_H_H22OO

ReactantsReactants ProductsProducts# C 3 # C 3 # C# C 3 3 # H 8# H 8 # H # H 88# O 10# O 10 # O # O 1010This now tells us the correct chemical equation This now tells us the correct chemical equation and exactly how much of each reactant was and exactly how much of each reactant was needed and how much of each product was needed and how much of each product was produced!!!!produced!!!!

Remember that atoms cannot be created or Remember that atoms cannot be created or destroyed; we must balance this equation destroyed; we must balance this equation using using coefficients. coefficients. Never change a Never change a subscript subscript to balance an equation!!to balance an equation!!

Atom Inventory or Counting Atoms – you Atom Inventory or Counting Atoms – you must be able to count atoms in order to must be able to count atoms in order to

balance an equation. There are two ways to balance an equation. There are two ways to designate numbers in a formula:designate numbers in a formula:

A.A. Subscripts – small numbers within Subscripts – small numbers within a formula of a compound. Tells the a formula of a compound. Tells the number of atoms in that compound.number of atoms in that compound.

1. MgCl1. MgCl22 – 1 atom of Mg and 2 of Cl – 1 atom of Mg and 2 of Cl

2. Sn2. Sn33NN22 – 3 atoms Sn and 2 N – 3 atoms Sn and 2 N

1.1. 3 Na3 Na22POPO44 – 3 formula units of sodium – 3 formula units of sodium phosphate (ionic)phosphate (ionic)

2.2. 2 CaCl2 CaCl22 – 2 formula units of calcium – 2 formula units of calcium chloride (ionic)chloride (ionic)

3.3. 5 H5 H22O – 5 molecules of water (molecular) O – 5 molecules of water (molecular)

4.4. 6 PI6 PI33 – 6 molecules of phosphorus triodide – 6 molecules of phosphorus triodide (molecular)(molecular)

5.5. 4 Na – 4 atoms of sodium (element)4 Na – 4 atoms of sodium (element)

B. Coefficient – the large number in front of B. Coefficient – the large number in front of the formula of a compound. Tells the the formula of a compound. Tells the number of molecules or formula units or number of molecules or formula units or atoms of an element.atoms of an element.

Practice writing an atom inventory for Practice writing an atom inventory for the following compounds:the following compounds:

a.a. aluminum phosphate aluminum phosphate

b.b. ammonium permanganate ammonium permanganate

c.c. 4Mg4Mg33(PO(PO44))22

Practice balancing the Practice balancing the following equations:following equations:

  

___H___H22O O ___H ___H22 + ___O + ___O22

2 2

___Pb(NO___Pb(NO33))22 + ___Na + ___Na ___NaNO ___NaNO33 + + ___Pb___Pb2 2

___C___C44HH1010 + ___O + ___O22 ___CO ___CO22 +___H +___H22OO2 10813

Energy in chemical Energy in chemical reactions: reactions:

Some reactions require more energy than is Some reactions require more energy than is produced; others produce more energy produced; others produce more energy than is required.than is required.

A. A. ExothermicExothermic Reaction: a reaction that Reaction: a reaction that releases energy; energy is a product and releases energy; energy is a product and is written on the right side of the arrow. is written on the right side of the arrow.

B. B. EndothermicEndothermic Reaction: a reaction that Reaction: a reaction that absorbs energy; energy is a reactant and absorbs energy; energy is a reactant and is written on the left of the arrow.is written on the left of the arrow.

Types of EnergyTypes of Energy

A.A. Potential energyPotential energy – the energy an – the energy an object has because of its position.object has because of its position.

B.B. Kinetic EnergyKinetic Energy – energy of motion. – energy of motion. The amount of kinetic energy an The amount of kinetic energy an object has depends on how fast the object has depends on how fast the object is moving (its velocity) and its object is moving (its velocity) and its mass:mass:

KE = ½ mvKE = ½ mv22

Write balanced chemical equations for the following:Write balanced chemical equations for the following:1. Iron + sulfur 1. Iron + sulfur iron (II) sulfide iron (II) sulfide 2. Zinc + copper (II) sulfate 2. Zinc + copper (II) sulfate zinc sulfate + copper zinc sulfate + copper3. Silver nitrate + sodium bromide 3. Silver nitrate + sodium bromide silver bromide + silver bromide +

sodium nitrate sodium nitrate 4. Water , in the presence of electricity and a Pt catalyst 4. Water , in the presence of electricity and a Pt catalyst

decomposes into hydrogen and oxygendecomposes into hydrogen and oxygen5. Ferric chloride + ammonium hydroxide 5. Ferric chloride + ammonium hydroxide ferric ferric

hydroxide + ammonium chloridehydroxide + ammonium chloride6. Iron + water 6. Iron + water hydrogen + ferric oxide hydrogen + ferric oxide7. Water plus dinitrogen trioxide 7. Water plus dinitrogen trioxide nitrous acid nitrous acid 8. Potassium hydroxide + phosphoric acid 8. Potassium hydroxide + phosphoric acid potassium potassium

phosphate + waterphosphate + water9. Methane gas reacts with oxygen gas to produce 9. Methane gas reacts with oxygen gas to produce

carbon dioxide gas, gaseous water, and energy.carbon dioxide gas, gaseous water, and energy.

Translate the following into a sentence and balancing Translate the following into a sentence and balancing the equation:the equation:

10. ___PbCl10. ___PbCl22 (aq) + ___Na (aq) + ___Na22CrOCrO44 (aq) (aq) ___PbCrO ___PbCrO44 (s) + (s) + ___NaCl (aq)___NaCl (aq)

11. ___Al11. ___Al22(SO(SO44))33 (aq) + ___Ca(OH) (aq) + ___Ca(OH)22 (aq) (aq) ___Al(OH) ___Al(OH)33 (s) (s) + ___CaSO + ___CaSO44 (s) (s)

Types of Chemical Types of Chemical ReactionsReactions::

There are 5 main types listed below and the general There are 5 main types listed below and the general formulas for each are givenformulas for each are given

1. synthesis (1. synthesis (or combinationor combination) reaction A + B ) reaction A + B AB AB

2. decomposition AB 2. decomposition AB A + B A + B

3. single replacement A + BC 3. single replacement A + BC AC + B AC + B

4. double replacement AB + CD 4. double replacement AB + CD AD + CB AD + CB

the positive ion is always written first.the positive ion is always written first.

5. combustion C5. combustion CxxHHyy + O + O2 2 CO CO22 + H + H22O O

here oxygen is always a reactant and carbon dioxide here oxygen is always a reactant and carbon dioxide

and water are always products in a COMPLETE and water are always products in a COMPLETE

combustion reaction.combustion reaction.

A. Combination or A. Combination or Synthesis:Synthesis:

Where 2 or more simple substances Where 2 or more simple substances (elements or compounds) combine to (elements or compounds) combine to form ONE complex substanceform ONE complex substance

Ex: 8Fe + SEx: 8Fe + S88 8FeS 8FeS

2Sr + O2Sr + O2 2 2SrO 2SrO

Mg + BrMg + Br22 MgBr MgBr22

Practice: Practice: Li + PLi + P44 ______________ ______________

NN22 + Al + Al ______________________ ______________________

ClCl22 + Ca + Ca ______________ ______________

Na + NNa + N22 _____________________ _____________________       

Special Combination or Synthesis Special Combination or Synthesis ReactionsReactions::

Special Combination or Synthesis ReactionsSpecial Combination or Synthesis Reactions: When : When one of the metals that has a variable charge on it is one of the metals that has a variable charge on it is an ion – when Fe, Pb, Cu, or Sn combines with an ion – when Fe, Pb, Cu, or Sn combines with another substance, which charge do you use?another substance, which charge do you use? Ex: Fe + OEx: Fe + O22 FeO or Fe FeO or Fe22OO3 3 ?????? Which is ?????? Which is the correct product??the correct product??

If one of these metals reacts with fluorine, If one of these metals reacts with fluorine, oxygen, or nitrogen (oxygen, or nitrogen (F, 0, NF, 0, N), these nonmetals will ), these nonmetals will pull the metal to its pull the metal to its HIGHEST HIGHEST chargecharge oror oxidation oxidation number. Otherwise, when these metals react in a number. Otherwise, when these metals react in a combination reaction, use their LOWEST charge or combination reaction, use their LOWEST charge or oxidation number when forming a new compoundoxidation number when forming a new compound

Practice:Practice:

Fe + OFe + O22 __________ __________

Pb + NPb + N2 2 _____________ _____________

Sn + SSn + S88 _________ _________

Cu + PCu + P44 ___________ ___________

Fe + BrFe + Br2 2 ___________ ___________

Cu + FCu + F22 _____________ _____________

A complex substance (compound) A complex substance (compound) decomposes into 2 or more simple decomposes into 2 or more simple substances. Heat or electricity is substances. Heat or electricity is usually required.usually required.Ex: Ex:

2NaCl 2NaCl 2 Na + Cl 2 Na + Cl22

8MgS 8MgS 8Mg + S 8Mg + S88

B. DecompositionB. Decomposition::

Special decomposition reactions to know:Special decomposition reactions to know:

2KClO2KClO3 3 2KCl + 3O 2KCl + 3O22 - all metal - all metal chlorates decompose into metal chloride chlorates decompose into metal chloride + O+ O22

CaCOCaCO3 3 CaO + CO CaO + CO22 - - metal carbonates metal carbonates decompose into a metal oxide + COdecompose into a metal oxide + CO22

2KOH2KOH K K22O + HO + H22O O - metal hydroxides - metal hydroxides decompose into a metal oxide + Hdecompose into a metal oxide + H22OO

Metal Oxides: Metal Oxides: if the metal is a heavy if the metal is a heavy metal (metal (Ag and heavierAg and heavier), decomposition ), decomposition will occur. If the metal is lighter than Ag, will occur. If the metal is lighter than Ag, nothing will happen except that you get a nothing will happen except that you get a HOT metal oxide.HOT metal oxide.

Ex: 2PbO Ex: 2PbO 2Pb + O 2Pb + O2 2 but but

MgO MgO hot magnesium oxide hot magnesium oxide

Practice: Practice:

PBrPBr5 5 ___________________ ___________________

CuCOCuCO3 3 _______________________ _______________________

KCl KCl _____________________ _____________________

AlFAlF33 ________________________ ________________________

NaClONaClO3 3 ___________________ ___________________

HI HI _________________________ _________________________

BiBi22OO33 ___________________ ___________________

NaNa22O O __________________________________________________

Where oxygen reacts with another substance, Where oxygen reacts with another substance, usually a hydrocarbon, resulting in the release usually a hydrocarbon, resulting in the release of energy, usually heat or light. A of energy, usually heat or light. A hydrocarbon is a compound containing carbon hydrocarbon is a compound containing carbon and hydrogen, although we will work and hydrogen, although we will work combustion reactions with compounds combustion reactions with compounds containing hydrogen, carbon and oxygen containing hydrogen, carbon and oxygen sometimes. There are 2 types of combustion sometimes. There are 2 types of combustion reactions:reactions:

IncompleteIncomplete – instead of CO – instead of CO22 being produced, the being produced, the products may be CO, COproducts may be CO, CO22 and/or C. Water is also a and/or C. Water is also a productproduct

CompleteComplete – carbon dioxide and water are the only – carbon dioxide and water are the only productsproducts

CHCH44 + 20 + 202 2 CO CO22 + 2H + 2H2200

Combustion ReactionsCombustion Reactions

Hint:Hint: Balancing combustion reactions: Balancing combustion reactions: FirstFirst - balance the - balance the carbonscarbons SecondSecond - balance the - balance the hydrogenshydrogens LastLast - balance the - balance the oxygensoxygens

Examples of Combustion Reactions:Examples of Combustion Reactions:

CC33HH88 + O + O22

CC22HH22 + 5O + 5O22

Ca + OCa + O22

Single-ReplacementSingle-Replacement Occurs when one element Occurs when one element

displaces another element in a displaces another element in a compound. compound.

You must check the You must check the “Activity “Activity Series of Metals" Series of Metals" (next(next slide) slide) to see if to see if the “lone” element is active or the “lone” element is active or “strong” enough to displace the “strong” enough to displace the element in the compound.element in the compound.

Activity Series of MetalsActivity Series of MetalsLiLiKK Ba Ba CaCaNaNaMgMg Al Al Zn Zn FeFeNiNiSnSnPbPb (H)(H)CuCuHgHgAgAg AuAu

Decreasing strength

↓

Practice:Practice:

Li + KCl Li + KCl _____________ _____________

Sn + ZnClSn + ZnCl22 ________________ ________________

Sn + HCl Sn + HCl _______________ _______________

Ni + HOH Ni + HOH ________________ ________________

Certain nonmetals, the Certain nonmetals, the halogenshalogens,, also behave like also behave like this. The order of “strength” this. The order of “strength” of the halogens isof the halogens is

FF22

ClCl22

BrBr22

II22

Decreasing strength

↓

Practice:Practice:

ClCl22 + NaBr + NaBr ______________ ______________

II22 + KBr + KBr ____________________ ____________________

FF22 + MgBr + MgBr22 _____________ _____________

BrBr22 + CaCl + CaCl22 _________________ _________________

EE. . Double-Replacement Double-Replacement reactionsreactions

Occur when the cations (positive ions) Occur when the cations (positive ions) “switch” places. You do NOT need the “switch” places. You do NOT need the “activity series of metals” list in these “activity series of metals” list in these reactions. When you switch places, be sure reactions. When you switch places, be sure to correctly write the formula of the new to correctly write the formula of the new compound!!!!!compound!!!!!

Ex: 2 NaCl + MgO Ex: 2 NaCl + MgO MgCl MgCl22 + Na + Na2O2O

2 KMn02 KMn04 4 + Na + Na22CC22OO44 2 NaMnO 2 NaMnO44 + + KK22CC22OO44

Practice:Practice:

(be sure to balance the equations too)(be sure to balance the equations too)

CuS0CuS044 + Al(OH) + Al(OH)33

CaCa33(P0(P044))22 + ZnCr0 + ZnCr044

1. Predict the products of the double-replacement 1. Predict the products of the double-replacement reaction and indicate the solubility of reaction and indicate the solubility of both both of the of the products by placing the symbol "(aq)" after the products by placing the symbol "(aq)" after the soluble product and the symbol "(s)" after the soluble product and the symbol "(s)" after the insoluble product.insoluble product.

Use the “Solubility Rules” handout (at end of notes) to Use the “Solubility Rules” handout (at end of notes) to determine the solubility. determine the solubility.

If the compound is soluble that means that it will If the compound is soluble that means that it will remain as ions in the solution, if it is insoluble then remain as ions in the solution, if it is insoluble then the compound precipitated out of the reaction (it the compound precipitated out of the reaction (it became the precipitate or solid).became the precipitate or solid).

2. If at least one INSOLUBLE product is formed 2. If at least one INSOLUBLE product is formed (which means a precipitate will form) the reaction (which means a precipitate will form) the reaction will occur!will occur!

3. If only SOUBLE products are formed then the 3. If only SOUBLE products are formed then the reaction will NOT occur (because no precipitate is reaction will NOT occur (because no precipitate is formed)! **Only exception is when the reaction formed)! **Only exception is when the reaction occurs and a gas is produced and not a ppt, but you occurs and a gas is produced and not a ppt, but you will learn about those in AP!!!!**will learn about those in AP!!!!**

4. If water is produced the reaction will 4. If water is produced the reaction will occur!occur!

5. If the reaction occurs and one of the 5. If the reaction occurs and one of the compounds formed is soluble then that compounds formed is soluble then that compound is written as ions and not as a compound is written as ions and not as a compound. compound.

ex. BaCOex. BaCO33 + CuSO + CuSO44 BaSO BaSO44(s) + CuCO(s) + CuCO3 3 (s)(s)

ex. Kex. K33POPO44 + NaOH + NaOH no reaction occurred no reaction occurred (no ppt)(no ppt)

ex. Naex. Na22S + Cd(NOS + Cd(NO33))22 Na Na++ + NO + NO33 + CdS(s) + CdS(s)

F. Net Ionic EquationsF. Net Ionic Equations – shows only the compounds and ions that undergo a chemical – shows only the compounds and ions that undergo a chemical change in a double replacement reactionchange in a double replacement reaction

Example: NaExample: Na22S + Cd(NOS + Cd(NO33))22 Na Na++ + NO + NO33 + CdS(s) + CdS(s)

Step 1: Convert the chemical equation to an overall ionic equation. All reactants are Step 1: Convert the chemical equation to an overall ionic equation. All reactants are shown as ions. For the products, all soluble ionic compounds are shown as dissociated shown as ions. For the products, all soluble ionic compounds are shown as dissociated ions and the precipitates are shown as solids. ions and the precipitates are shown as solids.

NaNa++ + S + S22 + Cd + Cd2+2+ + NO + NO33 Na Na++ + NO + NO33

+ CdS(s) + CdS(s)Step 2: All spectator ions (ions that do not take part in a chemical reaction and are found Step 2: All spectator ions (ions that do not take part in a chemical reaction and are found

as ions both before and after the reaction) are removed from the equation.as ions both before and after the reaction) are removed from the equation.SS22 + Cd + Cd2+2+ CdS(s) CdS(s)Examples of Double Replacement Reactions and Net Ionic Equations:Examples of Double Replacement Reactions and Net Ionic Equations:(Write the chemical equation for each as well as the net ionic equation.)(Write the chemical equation for each as well as the net ionic equation.)CuCOCuCO33 + NaCl + NaCl Rubidium Carbonate and Strontium Hydroxide combine. Rubidium Carbonate and Strontium Hydroxide combine. Demo Reaction Equation:Demo Reaction Equation: Practice Predicting ProductsPractice Predicting Products – If you know the 5 basic types of reactions, predicting the products of chemical – If you know the 5 basic types of reactions, predicting the products of chemical

reactions is not difficult. The first thing you need to do is to look at the reactants and determine what type of reactions is not difficult. The first thing you need to do is to look at the reactants and determine what type of reaction will probably occur. Always keep in mind the general formulas of the 5 types of reactions.reaction will probably occur. Always keep in mind the general formulas of the 5 types of reactions.

Practice: In this practice section, just tell what type of reaction it is.Practice: In this practice section, just tell what type of reaction it is.l. AlCll. AlCl33 ___________________ 2. C ___________________ 2. C22HH44 + 0 + 022 ___________________ ___________________3. Zn + AgNO3. Zn + AgNO33 _________________ 4. H _________________ 4. H220 0 ____________________________ ____________________________5. Al + P 5. Al + P ____________________ 6. NaI + MgS ____________________ 6. NaI + MgS ____________________ ____________________7. Cl7. Cl22 + NaBr + NaBr _________________ 8. C _________________ 8. C66HH12120066 + O + O22 _________________ _________________Predicting products - in this section, predict the actual products: (balance too)Predicting products - in this section, predict the actual products: (balance too)1. AlCl1. AlCl3 3 + Na + Na22COCO33 _______________________________________ _______________________________________2. Ni + MgSO4 2. Ni + MgSO4 ___________________________________________ ___________________________________________3. Cl3. Cl22 + K + K ___________________________________________ ___________________________________________4. C4. C55HH1212 + 0 + 022 __________________________________________ __________________________________________

Balancing PracticeBalancing Practice

For more help go to: For more help go to: http://richardbowles.tripod.com/chehttp://richardbowles.tripod.com/chemistry/balance.htm#part0mistry/balance.htm#part0

For some fun balancing equations For some fun balancing equations go to:go to:

http://www.mpcfaculty.net/mark_bihttp://www.mpcfaculty.net/mark_bishop/balancing_equations_tutorial.hshop/balancing_equations_tutorial.htmtm