Unit 3: Chemical Unit 3: Chemical ProcessesProcesses

Section 1: Chemicals in ActionSection 1: Chemicals in Action

ChemistryChemistry – the study of matter, its – the study of matter, its properties, and its changes or properties, and its changes or transformationstransformations

MatterMatter – anything that has mass – anything that has mass and takes up spaceand takes up space

Matter has both physical and Matter has both physical and chemical propertieschemical properties

MatterMatter

Matter is either classified as a pure Matter is either classified as a pure substance or as a mixturesubstance or as a mixture

Pure substancePure substance – one in which all the – one in which all the particles that make up the substance are particles that make up the substance are the samethe same

E.g. Pure WaterE.g. Pure Water

Pure substances can be further classified Pure substances can be further classified as elements or compoundsas elements or compounds

Elements are pure substances that Elements are pure substances that cannot be broken down into simpler cannot be broken down into simpler substances (made of only one type of substances (made of only one type of atom)atom)

E.g. oxygen, hydrogen, …E.g. oxygen, hydrogen, …

Compounds are pure substances that Compounds are pure substances that are made of two or more different are made of two or more different elements in a fixed proportionelements in a fixed proportion

E.g. carbon dioxide, sodium chloride, …E.g. carbon dioxide, sodium chloride, …

Properties of MatterProperties of Matter

Matter has both physical and chemical Matter has both physical and chemical propertiesproperties

Physical propertyPhysical property – is a characteristic of a – is a characteristic of a substance (color, hardness, odour, solubility, substance (color, hardness, odour, solubility, state, melting and boiling point, size)state, melting and boiling point, size)

– A physical change is a change in the size or form A physical change is a change in the size or form of a substance, which does not change the of a substance, which does not change the chemical properties of the substancechemical properties of the substance

Chemical PropertyChemical Property – is a characteristic – is a characteristic behaviour that occurs when a substance behaviour that occurs when a substance changes to a new substancechanges to a new substance

A chemical change is also called a A chemical change is also called a chemical reaction. It involves changing chemical reaction. It involves changing one substance into one or more different one substance into one or more different substances with different propertiessubstances with different properties

The starting materials in a chemical The starting materials in a chemical reaction are called the reaction are called the reactantsreactants and the and the new materials are called the new materials are called the productsproducts..

Chemical testsChemical tests – are distinctive – are distinctive chemical reactions that can be used chemical reactions that can be used to identify an unknown substanceto identify an unknown substance

HomeworkHomework

Questions 1, 2, 4, and 5 page 175.Questions 1, 2, 4, and 5 page 175.

Elements and the Periodic Elements and the Periodic TableTable

Periodic TablePeriodic Table – a structured – a structured arrangement of elementsarrangement of elements

Elements on the periodic table are Elements on the periodic table are grouped into grouped into chemical familieschemical families – – groups of elements in the same groups of elements in the same vertical column of the periodic table. vertical column of the periodic table. They tend to share similar physical They tend to share similar physical and chemical properties.and chemical properties.

Special Named FamiliesSpecial Named Families

Alkali metals – group 1 elementsAlkali metals – group 1 elements

Alkaline earth metals – group 2 Alkaline earth metals – group 2 elementselements

Noble gases – group 18 elementsNoble gases – group 18 elements

Halogens – group 17 elementsHalogens – group 17 elements

Elements and Atomic Elements and Atomic StructureStructure

Atoms are composed of three subatomic particles Atoms are composed of three subatomic particles (protons, neutrons, electrons)(protons, neutrons, electrons)

ProtonsProtons – positively charge particles found in the – positively charge particles found in the nucleus of the atom. Each proton has a mass of 1nucleus of the atom. Each proton has a mass of 1

NeutronsNeutrons – neutral particles found in the nucleus – neutral particles found in the nucleus of the atom. Each neutron has a mass of 1of the atom. Each neutron has a mass of 1

Electrons Electrons – negatively charged particles with – negatively charged particles with almost no mass and can be found in orbits almost no mass and can be found in orbits surrounding the nucleussurrounding the nucleus

The number of electrons in an atom is The number of electrons in an atom is equal to the number of protons.equal to the number of protons.

Electrons that are in the outer orbit Electrons that are in the outer orbit ((valence shellvalence shell) have greater energy ) have greater energy levels and a greater probability of being levels and a greater probability of being involved in a chemical reaction. These involved in a chemical reaction. These electrons are called electrons are called valence electronsvalence electrons..– Think of Bohr-Rutherford diagrams…Think of Bohr-Rutherford diagrams…

Bohr – Rutherford DiagramsBohr – Rutherford Diagrams

Each orbit around the nucleus of an atom Each orbit around the nucleus of an atom contain a specific number of electrons. contain a specific number of electrons. – 11stst orbit = 2 electrons orbit = 2 electrons– 22ndnd orbit = 8 electrons orbit = 8 electrons– 33rdrd orbit = 8 electrons orbit = 8 electrons

The electrons fill the orbits in order. The electrons fill the orbits in order. Each orbit must be filled completely Each orbit must be filled completely before electrons can be placed in a new before electrons can be placed in a new orbit.orbit.

Sample Bohr – Rutherford Sample Bohr – Rutherford DiagramsDiagrams

Create a diagram Create a diagram for Nitrogenfor Nitrogen

1. Determine the number of 1. Determine the number of electrons (7)electrons (7)

2. Draw the first orbit with the 2. Draw the first orbit with the maximum number of maximum number of electrons allowed (2)electrons allowed (2)

3. Draw the second orbit with 3. Draw the second orbit with the remaining electrons (5)the remaining electrons (5)

4. Draw the nucleus with the 4. Draw the nucleus with the protons and neutronsprotons and neutrons

7p

7n

You Try It (1)You Try It (1)

Create a Bohr – Rutherford diagram Create a Bohr – Rutherford diagram for Magnesiumfor Magnesium

AnswerAnswer Determine the number of electrons, 12Determine the number of electrons, 12 Draw the first orbit (2)Draw the first orbit (2) Draw the second orbit (8)Draw the second orbit (8) Draw the third orbit (2)Draw the third orbit (2) Draw the nucleus Draw the nucleus

with the protons and with the protons and

neutronsneutrons 12p

12n

You Try It (2)You Try It (2)

Create a diagram for SodiumCreate a diagram for Sodium

AnswerAnswer

Determine the number Determine the number of electrons (11)of electrons (11)

Draw the first orbital Draw the first orbital (2)(2)

Draw the second Draw the second orbital (8)orbital (8)

Draw the third orbital Draw the third orbital (1)(1)

Draw the nucleus with Draw the nucleus with the protons and the protons and neutrons.neutrons.

You Try It (3)You Try It (3)

Create a diagram for NeonCreate a diagram for Neon

AnswerAnswer

Determine the number of Determine the number of electrons (10)electrons (10)

Draw the first orbit (2)Draw the first orbit (2)

Draw the second orbit (8)Draw the second orbit (8)

Draw the nucleus with the Draw the nucleus with the protons and neutrons.protons and neutrons.

10p

10n

The noble gases (column 18) are The noble gases (column 18) are considered to be fairly stable.considered to be fairly stable.

– Look at the arrangement of the Look at the arrangement of the electrons in the noble gases by drawing electrons in the noble gases by drawing a Bohr – Rutherford diagram for He, Ne, a Bohr – Rutherford diagram for He, Ne, and Ar. What do you notice about the and Ar. What do you notice about the arrangement of the electrons?arrangement of the electrons?

In some compounds, electrons are In some compounds, electrons are transferred from one atom to another transferred from one atom to another to create a stable electron to create a stable electron arrangement (like the noble gases)arrangement (like the noble gases)

Create a Bohr – Rutherford Diagram Create a Bohr – Rutherford Diagram for Lithium. for Lithium.

Notice that lithium has Notice that lithium has two electrons in the first two electrons in the first orbit and one in its outer orbit and one in its outer orbit (valence shell).orbit (valence shell).

If lithium loses one If lithium loses one electron it will have the electron it will have the same electron same electron arrangement as helium.arrangement as helium.

However the charge on However the charge on the atom is no longer the atom is no longer neutral. It has 3 protons neutral. It has 3 protons (positive charges) and 2 (positive charges) and 2 electrons (negative electrons (negative charges) giving an charges) giving an overall charge of 1+overall charge of 1+

P = 3

N = 4

An ion is a charged atom in which An ion is a charged atom in which the number of electrons is different the number of electrons is different from the number of protonsfrom the number of protons

The term ionic charge is used to The term ionic charge is used to describe the overall charge an ion describe the overall charge an ion has.has.

Example Li which has lost an electron is Example Li which has lost an electron is written as Liwritten as Li++..

Create a Bohr – Rutherford diagram for Create a Bohr – Rutherford diagram for calcium.calcium.

How many electrons would calcium How many electrons would calcium have to lose in order to become stable have to lose in order to become stable like a noble gas?like a noble gas?

What would the ionic charge be on Ca? What would the ionic charge be on Ca?

Metals tend to lose their electrons Metals tend to lose their electrons and nonmetals tend to gain and nonmetals tend to gain electrons.electrons.

YOU DO ITYOU DO IT

What would most likely to happen to What would most likely to happen to the electrons in fluorine if it was to the electrons in fluorine if it was to become stable like a noble gas? become stable like a noble gas?

What would be the ionic charge on What would be the ionic charge on fluorine if this happened?fluorine if this happened?

Fluorine would gain one electrons Fluorine would gain one electrons (nonmetal).(nonmetal).

Fluorine would have a net ionic Fluorine would have a net ionic charge of “1charge of “1--” and the atom would be ” and the atom would be represented as “Frepresented as “F--” (fluoride ion)” (fluoride ion)

The ending “ide” is added to nonmetal ionsThe ending “ide” is added to nonmetal ions

YOU DO ITYOU DO IT

What would most likely to happen to What would most likely to happen to the electrons in sulfur if it was to the electrons in sulfur if it was to become stable like a noble gas? become stable like a noble gas? What would be the ionic charge on What would be the ionic charge on sulfur?sulfur?

Sulfur would gain two electronsSulfur would gain two electrons

SS2-2- (sulfide ion) (sulfide ion)

HomeworkHomework 1. Create a Bohr – Rutherford diagram for:1. Create a Bohr – Rutherford diagram for:

– BoronBoron– ChlorineChlorine– NitrogenNitrogen– BerylliumBeryllium

2a. Create a Bohr – Rutherford diagram for 2a. Create a Bohr – Rutherford diagram for the stable ion formed by each of the above the stable ion formed by each of the above atomsatoms

b. State the ionic charge on each of the ions, b. State the ionic charge on each of the ions, and write the name of the atom in ionic form.and write the name of the atom in ionic form.

How Elements Form How Elements Form CompoundsCompounds

Compounds are made by combining Compounds are made by combining elements together.elements together.

Ionic Compound Ionic Compound – is formed when – is formed when positive and negative ions join together. positive and negative ions join together. The ions combine in a fashion that The ions combine in a fashion that generally leaves the ionic compound with generally leaves the ionic compound with a neutral charge.a neutral charge.

Molecular CompoundMolecular Compound – are formed when – are formed when nonmetals combine with other nonmetals.nonmetals combine with other nonmetals.

Chemical FormulaChemical Formula

A chemical formula is a combination A chemical formula is a combination of symbols that represent a of symbols that represent a compoundcompound

– Example: magnesium chloride (MgClExample: magnesium chloride (MgCl22) ) describes a compound with one describes a compound with one magnesium ion to two chloride ionsmagnesium ion to two chloride ions

HomeworkHomework

Answer questions 2 and 3 on page Answer questions 2 and 3 on page 189. For part b construct a Bohr – 189. For part b construct a Bohr – Rutherford Diagram instead of a Bohr Rutherford Diagram instead of a Bohr diagram.diagram.

Ionic CompoundsIonic Compounds

Metals and nonmetals combine to Metals and nonmetals combine to form compounds by sharing form compounds by sharing electrons (metals lose electrons to electrons (metals lose electrons to form positive ions and nonmetals form positive ions and nonmetals gain electrons to form negative ions)gain electrons to form negative ions)

– Example: Aluminum chloride (AlClExample: Aluminum chloride (AlCl33) Al = ) Al = 33++ and Cl = 1 and Cl = 1-- (3+) + 3(1-) = 0 (3+) + 3(1-) = 0

Writing Formulas For Ionic Writing Formulas For Ionic CompoundsCompounds

What is the formula for the ionic compound formed What is the formula for the ionic compound formed by calcium and iodine?by calcium and iodine?

Steps:Steps:1.1. Write the symbols, with the metal first.Write the symbols, with the metal first.

CaCa II

2.2. Write the ionic charge above each symbol to indicate the Write the ionic charge above each symbol to indicate the stable ion that each element forms.stable ion that each element forms.

2+2+ 1-1-CaCa II

3.3. Determine how many ions of each type you need so that the Determine how many ions of each type you need so that the total ionic charge is zero.total ionic charge is zero.

One CaOne Ca22++ ion will balance the charge of two I ion will balance the charge of two I--

ions.ions.

4.4. Write the formula using subscripts to indicate the number of Write the formula using subscripts to indicate the number of ions of each typeions of each type

CaICaI22

YOU TRY ITYOU TRY IT

What is the formula for the ionic What is the formula for the ionic compound formed by aluminum and compound formed by aluminum and sulfur?sulfur?

ANSWERANSWER

AlAl22SS33

YOU TRY IT 2YOU TRY IT 2

What is the formula for the ionic What is the formula for the ionic compound formed by aluminum and compound formed by aluminum and sulfur?sulfur?

ANSWERANSWER

AlAl22SS33

YOU TRY IT 3YOU TRY IT 3

What is the formula for the ionic What is the formula for the ionic compound formed by nickel and compound formed by nickel and oxygen?oxygen?

ANSWERANSWER

NiONiO

Naming Ionic CompoundsNaming Ionic Compounds

The name of the metal is first followed The name of the metal is first followed by the name of the nonmetal. by the name of the nonmetal. However, the ending of the name for However, the ending of the name for the nonmetal changes to “ide”the nonmetal changes to “ide”

Example: Calcium and Iodine become Example: Calcium and Iodine become Calcium iodideCalcium iodide

Example: Aluminum and Sulfur become Example: Aluminum and Sulfur become Aluminum sulfideAluminum sulfide

Transition Metal ChargesTransition Metal Charges ScSc 33++

TiTi 44++ 33++

VV 55++ 44++

CrCr 33++ 22++

MnMn 22++ 44++

FeFe 33++ 22++

CoCo 22++ 33++

NiNi 22++ 33++

CuCu 22++ ++

ZnZn 22++

PdPd 22++ 44++

AgAg ++

CdCd 22++

SnSn 44++ 22++

SbSb 33++ 55++

PtPt 44++ 22++

AuAu 33++ ++

HgHg 22++ ++

TlTl ++ 33++

PbPb 22++ 44++

BiBi 33++ 55++

PoPo 22++ 44++

CeCe 3 3++

PrPr 3 3++

NdNd 3 3++

PmPm 3 3++

SmSm 3 3++

EuEu 3 3++ 22++

GdGd 3 3++

TbTb 3 3++

DyDy 3 3++

HoHo 3 3++

ErEr 3 3++

TmTm 3 3++

YbYb 3 3++

LuLu 3 3++

AcAc 3 3++

ThTh 4 4++

PaPa 5 5++

UU 6 6++ 44++

NpNp 5 5++

PuPu 4 4++ 66++

AmAm 3 3++

CmCm 3 3++

BkBk 3 3++

CfCf 3 3++

ExamplesExamples Name or write the chemical formula for Name or write the chemical formula for

the following molecules.the following molecules.– 1) Tin (IV) oxide 1) Tin (IV) oxide – 2)PbO2)PbO– Platinum (II) sulfidePlatinum (II) sulfide– AgAg33NN

AnswersAnswers– 1) SnO1) SnO22

– Lead (II) oxideLead (II) oxide– PtSPtS– Silver (I) nitrideSilver (I) nitride

HomeworkHomework

Read page 195Read page 195

Questions 1, 3 – 9 on page 195Questions 1, 3 – 9 on page 195

Polyatomic CompoundsPolyatomic Compounds

Are formed when metals combine Are formed when metals combine with polyatomic ions (refer to Table 2 with polyatomic ions (refer to Table 2 on page 196 for a list of polyatomic on page 196 for a list of polyatomic ions and their charge)ions and their charge)

Polyatomic IonsPolyatomic Ions – groups of atoms – groups of atoms that tend to stay together and carry that tend to stay together and carry an overall ionic chargean overall ionic charge

Writing Formulas for Writing Formulas for Polyatomic CompoundsPolyatomic Compounds

RulesRules1.1. Write the symbols of the metal and of Write the symbols of the metal and of

the polyatomic group.the polyatomic group.

2.2. Write the ionic chargesWrite the ionic charges

3.3. Choose the number of ions to balance Choose the number of ions to balance the charge.the charge.

4.4. Write the formula using subscriptsWrite the formula using subscripts

Common Polyatomic IonsCommon Polyatomic Ions HH33OO++ hydronium hydronium NHNH44

++ ammonium ammonium HCOHCO33

-- bicarbonatebicarbonate HSOHSO44

- - hydrogen sulfatehydrogen sulfate CHCH33COCO22

-- acetateacetate ClOClO44

- - perchlorateperchlorate NONO33

- - nitratenitrate ClOClO33

- - chloratechlorate NONO22

-- nitrite nitrite ClOClO22

-- chloritechlorite MnOMnO44

-- permanganatepermanganate ClOClO-- hypochloritehypochlorite

CNCN- - cyanidecyanide OHOH-- hydroxidehydroxide COCO33

22- - carbonatecarbonate OO22

22- - peroxideperoxide SOSO44

22- - sulfatesulfate CrOCrO44

2-2- chromatechromate SOSO33

2- 2- sulfite sulfite CrCr22OO77

2-2- dichromatedichromate SS22OO33

2-2- thiosulfatethiosulfate HPOHPO44

2-2- hydrogen phosphatehydrogen phosphate POPO44

3- 3- phosphatephosphate AsOAsO44

3-3- arsenatearsenate BOBO33

3-3- borateborate

YOU TRY IT 1YOU TRY IT 1

What is the formula for the ionic What is the formula for the ionic compound formed by sodium and compound formed by sodium and sulfate?sulfate?

ANSWERANSWER

NaNa22SOSO44

YOU TRY IT 2YOU TRY IT 2

What is the formula for the ionic What is the formula for the ionic compound formed by lead (IV) and compound formed by lead (IV) and carbonate?carbonate?

ANSWERANSWER

Pb(COPb(CO33))22

Naming Polyatomic Naming Polyatomic CompoundsCompounds

The name of a polyatomic compound The name of a polyatomic compound is simply a combination of the name is simply a combination of the name of the metal and the name of the of the metal and the name of the polyatomic ion.polyatomic ion.

– Example: Potassium ion and carbonate Example: Potassium ion and carbonate ion form Potassium carbonate.ion form Potassium carbonate.

OxyacidsOxyacids

Are compounds formed when Are compounds formed when hydrogen combines with polyatomic hydrogen combines with polyatomic ions that contain oxygen.ions that contain oxygen.

Table 3 on page 198 list some Table 3 on page 198 list some common oxyacids.common oxyacids.

Naming AcidsNaming Acids Acids containing ions ending with Acids containing ions ending with ideide

often become often become hydro -ic acidhydro -ic acid

– ClCl-- chloridechloride HCl HCl hydrochloric acid hydrochloric acid – FF-- fluoridefluoride HF HF hydrofluoric acid hydrofluoric acid

– SS22-- sulfidesulfide HH22S S hydrosulfuric acidhydrosulfuric acid

Acids containing ions ending with Acids containing ions ending with ateate usually become usually become --ic acidic acid

– CHCH33COCO22-- acetate acetate CHCH33COCO22H H acetic acetic

acidacid– COCO33

2-2- carbonate carbonate HH22COCO33 carbonic acidcarbonic acid– BOBO33

3-3- borate borate HH33BOBO33 boric acid boric acid – NONO33

-- nitrate nitrate HNOHNO33 nitric acidnitric acid– SOSO44

2-2- sulfate sulfate HH22SOSO44 sulfuric acidsulfuric acid– ClOClO44

-- perchlorate perchlorate HClOHClO44 perchloric acidperchloric acid– POPO44

3-3- phosphate phosphate HH33POPO44 phosphoric acidphosphoric acid– MnOMnO44

-- permanganate permanganate HMnOHMnO44 permanganic permanganic acidacid

– CrOCrO442-2- chromate chromate HH22CrOCrO44 chromic acidchromic acid

– ClOClO33-- chlorate chlorate HClOHClO33 chloric acid chloric acid

Acids containing ions ending with Acids containing ions ending with iteite usually become usually become -ous acid-ous acid

– ClOClO22-- chlorite chlorite HClOHClO22 chlorous acid chlorous acid

– NONO22-- nitrite nitrite HNOHNO22 nitrous acid nitrous acid

– SOSO332-2- sulfite sulfite HH22SOSO33 sulfurous acid sulfurous acid

– ClOClO-- hypochlorite hypochlorite HClO HClO hypochlorous acid hypochlorous acid

HomeworkHomework

Questions 3 – 4, 6 – 7 on page 198Questions 3 – 4, 6 – 7 on page 198

Molecular CompoundsMolecular Compounds Most of the compounds you encounter Most of the compounds you encounter

every day do not contain ions but neutral every day do not contain ions but neutral groups of atoms called moleculesgroups of atoms called molecules

These compounds form These compounds form covalent bondscovalent bonds – – a shared pair of electrons between two a shared pair of electrons between two nonmetal atoms that holds the atoms nonmetal atoms that holds the atoms together in a molecule.together in a molecule.

– Example: Hydrogen gas is a molecule formed Example: Hydrogen gas is a molecule formed when two hydrogen atoms combine and share when two hydrogen atoms combine and share their electrontheir electron Make a diatomic molecule (refer to table 1 on page Make a diatomic molecule (refer to table 1 on page

202 for a list of diatomic molecules) 202 for a list of diatomic molecules)

Writing Formulas for Molecular Writing Formulas for Molecular CompoundsCompounds

The combining capacity of a nonmetal is a The combining capacity of a nonmetal is a measure of the number of covalent bonds measure of the number of covalent bonds that it will need to form a stable moleculethat it will need to form a stable molecule

Rules for writing molecular formulasRules for writing molecular formulas1.1. Write the symbols with the left-hand element Write the symbols with the left-hand element

first with the combining capacity.first with the combining capacity.

2.2. Crisscross the combining capacities to Crisscross the combining capacities to produce subscripts.produce subscripts.

3.3. Reduce the subscripts if possible.Reduce the subscripts if possible.

YOU TRY IT 1YOU TRY IT 1

How would you write the formula for How would you write the formula for a compound formed between carbon a compound formed between carbon and sulfur?and sulfur?

AnswerAnswer

CSCS22

Naming Molecular Naming Molecular CompoundsCompounds

The names of molecular compounds often The names of molecular compounds often contain prefixes that are used to count the contain prefixes that are used to count the number of atoms when the same two number of atoms when the same two elements form different combinations.elements form different combinations.

Prefixes in Molecular Prefixes in Molecular CompoundsCompounds

PrefixPrefix NumbeNumberr

Example (formula)Example (formula)

Mon(o)-Mon(o)- 11 Carbon monoxide (CO)Carbon monoxide (CO)

Di-Di- 22 Carbon dioxide (COCarbon dioxide (CO22))

Tri- Tri- 33 Sulfur trioxide (SOSulfur trioxide (SO33))

Tetra-Tetra- 44 Carbon tetrafluoride (CFCarbon tetrafluoride (CF44))

Pent(a)-Pent(a)- 55 Phosphorus pentabromide Phosphorus pentabromide (PBr(PBr55))

HomeworkHomework

Questions 4 – 6 on page 204Questions 4 – 6 on page 204

Read pages 205 – 210Read pages 205 – 210

What is the difference between a What is the difference between a natural product and a synthetic natural product and a synthetic product?product?

What is a polymer?What is a polymer?