Types of Measurement Qualitative measurement: uses words to describe something. (i.e. A yellow-green...

Types of MeasurementTypes of MeasurementQualitative measurementQualitative measurement: uses words to : uses words to

describe something. (i.e. A yellow-green describe something. (i.e. A yellow-green

gas was released.)gas was released.)

Quantitative measurementQuantitative measurement: uses numbers : uses numbers

to describe something. (i.e. The oxide has to describe something. (i.e. The oxide has

a mass of 1.567 grams.)a mass of 1.567 grams.)

Temperature ScalesTemperature ScalesCelsius, Kelvin, FahrenheitCelsius, Kelvin, FahrenheitConverting Converting Celsius to KelvinCelsius to Kelvin: : C + 273 = ____KC + 273 = ____K

a. Example: 25 C = ______a. Example: 25 C = ______ 25 + 273 = 25 + 273 = 298 K298 K

Converting Converting Kelvin to CelsiusKelvin to Celsius::K - 273 = ______CK - 273 = ______C

a. Example: 300 K = _________Ca. Example: 300 K = _________C300 – 273 = 300 – 273 = 27 C27 C

Classification of MatterClassification of MatterThe law of conservation of matter states that The law of conservation of matter states that

matter can neither be created nor destroyed.matter can neither be created nor destroyed.

Matter Matter Are the properties and composition constant?

no yes

mixture pure substancephysical change

Is chemical separationinto simpler substancespossible?

yes

chemical compoundwater, sodium chloride

seawatermudfruit salad

no

elementoxygen, gold,sulfur

anything that has mass and occupies space

Classification of MatterClassification of MatterCompound:Compound: A substance with a constant A substance with a constant composition that can be broken down into composition that can be broken down into elements by chemical processes.elements by chemical processes.

Element:Element: A substance that cannot be A substance that cannot be decomposed into simpler substances by decomposed into simpler substances by chemical means.chemical means.

Classification of MatterClassification of MatterMixtureMixture

1. Components of two or more components that 1. Components of two or more components that

can be separated by physical means, such can be separated by physical means, such

as chromatography, filtration, or distillationas chromatography, filtration, or distillation

2. No chemical bonds between the separate 2. No chemical bonds between the separate

partsparts

3. Components can vary in composition3. Components can vary in composition

Classification of MatterClassification of MatterTwo kinds of mixturesTwo kinds of mixtures1. 1. Homogeneous mixtures (solutions)Homogeneous mixtures (solutions)

A. can contain solids, liquids, or gasesA. can contain solids, liquids, or gasesB. are evenly mixed, appear as one B. are evenly mixed, appear as one component even though there are two or component even though there are two or more parts. more parts.

1. Examples: plain jello, air, and cool 1. Examples: plain jello, air, and cool aidaid

Classification of MatterClassification of Matter2. 2. Heterogeneous mixturesHeterogeneous mixtures

A. are unevenly mixedA. are unevenly mixedB. can see separate componentsB. can see separate componentsC. Examples: dirt, concrete, salad dressingC. Examples: dirt, concrete, salad dressing

Classification of MatterClassification of MatterClassify these as an element, a compound, a Classify these as an element, a compound, a heterogeneous mixture, or a homogeneous heterogeneous mixture, or a homogeneous mixture. mixture. 1. concrete1. concrete2. air2. air3. salt3. salt4. gold4. gold5. helium5. helium6. tea6. tea7. salt water7. salt water

Metric PrefixesMetric PrefixesMetric Prefixes and Powers of 10Metric Prefixes and Powers of 10

1. mega = 101. mega = 106 6 (megagrams) (Mg)(megagrams) (Mg)

2. kilo = 102. kilo = 103 3 (kilograms) (kg)(kilograms) (kg)

3. base = 103. base = 100 0 (grams) (g)(grams) (g)

4. centi = 104. centi = 10-2 -2 (centigrams) (cg)(centigrams) (cg)

5. milli = 105. milli = 10-3 -3 (milligrams) (mg)(milligrams) (mg)

6. micro = 106. micro = 10-6-6 (micrograms) ( (micrograms) (μμg)g)

6000 mg _____ g _____ kg _____Mg6000 mg _____ g _____ kg _____Mg

Precision vs. AccuracyPrecision vs. AccuracyPrecisionPrecision refers to how close a series of refers to how close a series of

measurements are to one another. measurements are to one another.

1. Replication of result / value1. Replication of result / value

AccuracyAccuracy refers to how close a measured value refers to how close a measured value

is to an accepted value.is to an accepted value.

1. True or correct result / value1. True or correct result / value

Seven Base SI UnitsSeven Base SI Units1. Length meter (m) 1. Length meter (m)

2. Mass kilogram (kg)2. Mass kilogram (kg)

3. Time second (s)3. Time second (s)

4. Temperature Kelvin (K)4. Temperature Kelvin (K)

5. Current Ampere (amp)5. Current Ampere (amp)

6. Amount mole (mol)6. Amount mole (mol)

7. Luminousity7. Luminousity candela (cd) candela (cd)

Derived UnitsDerived UnitsDerived UnitsDerived Units are combinations of two or more are combinations of two or more

units. units.

1. Examples: speed = mi/hr or ft/sec 1. Examples: speed = mi/hr or ft/sec

density = mass/volumedensity = mass/volume

area = (length) (width)area = (length) (width)

DensityDensityDensityDensity is the mass of a substance per unit is the mass of a substance per unit

volume of the substance.volume of the substance.

1. density = mass/volume (g/ml or g/cm1. density = mass/volume (g/ml or g/cm33))

2. Water (the standard for all density values) = 2. Water (the standard for all density values) =

1.0 g/ml1.0 g/ml

3. 1ml = 1cm3. 1ml = 1cm33

4. What is the volume of a 50 g metal block 4. What is the volume of a 50 g metal block

with a density of 5 g/cmwith a density of 5 g/cm33 ? ?

5. d = m/V, m = dV, V = m/d5. d = m/V, m = dV, V = m/d

The Chemists’ Shorthand: The Chemists’ Shorthand: Atomic SymbolsAtomic Symbols

The Chemists’ Shorthand: The Chemists’ Shorthand: Atomic SymbolsAtomic Symbols

K = element symbol

39

19

mass number =

atomic number =

Atomic StructureAtomic Structureatomic numberatomic number = number of protons = number of protons1. also represents number of electrons in an 1. also represents number of electrons in an atomatom

mass numbermass number = total number of protons and = total number of protons and neutronsneutrons

Atomic StructureAtomic StructureIn uncharged (neutral) atoms, the atomic In uncharged (neutral) atoms, the atomic

number equals the number of protons equals number equals the number of protons equals

the number of electrons.the number of electrons.

If an atom is charged (different number of If an atom is charged (different number of

protons and electrons), then it is called an ion.protons and electrons), then it is called an ion.

1. A (+) charged ion is called a 1. A (+) charged ion is called a cationcation..

2. A (-) charged ion is called an 2. A (-) charged ion is called an anionanion..

Atomic StructureAtomic StructureIsotopes are atoms of the same element (with Isotopes are atoms of the same element (with

the same number of protons) but different the same number of protons) but different

number of neutrons.number of neutrons.

1. An element is defined by the number of 1. An element is defined by the number of

protons in the atom’s nucleus. protons in the atom’s nucleus.

A. Example: carbon – 12 (12 neutrons); A. Example: carbon – 12 (12 neutrons);

carbon – 14 (14 neutrons)carbon – 14 (14 neutrons)

Periodic Table of the ElementsPeriodic Table of the Elements

Atomic StructureAtomic Structure

Atomic StructureAtomic StructureParticleParticle Mass Mass Charge Charge

ElectronElectron 9.11 x 109.11 x 10-31-31 - 1 - 1

ProtonProton 1.67 x 101.67 x 102727 + 1+ 1

NeutronNeutron 1.67 x 101.67 x 102727 0 0

Periodic Table of the ElementsPeriodic Table of the ElementsPeriodic Table of the ElementsPeriodic Table of the ElementsGroupsGroups (vertical - up and down the table)(vertical - up and down the table)

1A = alkali metals1A = alkali metals

2A = alkaline earth metals2A = alkaline earth metals

7A = halogens7A = halogens

8A = noble gases8A = noble gases

PeriodsPeriods (horizontal - across the table) (horizontal - across the table)

numbered 1-7numbered 1-7

Periodic Table of the ElementsPeriodic Table of the ElementsMetals vs NonmetalsMetals vs Nonmetals - see staircase on the - see staircase on the Periodic table Periodic table 1. 1. MetalsMetals - to the left of the staircase; mostly - to the left of the staircase; mostly solids; conduct electricity; lose electrons to solids; conduct electricity; lose electrons to form positive ionsform positive ions2. 2. NonmetalsNonmetals - to the right of the staircase; - to the right of the staircase; most are gases; nonconductors of electricity; most are gases; nonconductors of electricity; gain electrons to form negative ionsgain electrons to form negative ions3. 3. MetalloidsMetalloids - border the staircase; have - border the staircase; have properties of metals and nonmetals. properties of metals and nonmetals.

Periodic Table of the ElementsPeriodic Table of the ElementsThere are 7 periods on the periodic table There are 7 periods on the periodic table

numbered 1 - 7. numbered 1 - 7.

1. They represent the major energy levels (n). 1. They represent the major energy levels (n).

2. They are horizontal rows that extend from 2. They are horizontal rows that extend from

left to right. left to right.

Ex: Period 2 includes Li - Ne.Ex: Period 2 includes Li - Ne.

Periodic Table of the ElementsPeriodic Table of the ElementsGroupsGroups

1. IA - 1. IA - Alkali MetalsAlkali Metals (1 valence electron) very (1 valence electron) very reactivereactive

2. IIA - 2. IIA - Alkaline Earth MetalsAlkaline Earth Metals (2 valence (2 valence electrons)electrons)

3. VIIA - 3. VIIA - HalogensHalogens (7 valence electrons) very (7 valence electrons) very reactivereactive

4. VIIIA – 4. VIIIA – Noble GasesNoble Gases (8 valence electrons (8 valence electrons except for Helium) non-reactive (very stable) except for Helium) non-reactive (very stable)

Periodic Table of the ElementsPeriodic Table of the ElementsRepresentative ElementsRepresentative Elements - The Group “A” - The Group “A”

Elements which include all the Groups IA to Elements which include all the Groups IA to VIIIAVIIIA

Transition Elements Transition Elements - The Group “B” Elements - The Group “B” Elements

Periodic Table of the ElementsPeriodic Table of the ElementsLanthanide SeriesLanthanide Series - the 4f row that includes - the 4f row that includes

# 57 (Lanthanum) through # 71 Lu# 57 (Lanthanum) through # 71 Lu

Actinide SeriesActinide Series - the 5f row that includes # 89 - the 5f row that includes # 89

Ac (Actinum) through # 102 NoAc (Actinum) through # 102 No

Periodic Table of the ElementsPeriodic Table of the ElementsAtomic RadiusAtomic Radius - the distance from the center of - the distance from the center of

the nucleus to the outermost valence shellthe nucleus to the outermost valence shell

Periodic TrendPeriodic Trend - The atomic radius increases as - The atomic radius increases as

one moves down the group. The atomic radius one moves down the group. The atomic radius

decreases as one moves across a period.decreases as one moves across a period.

Inorganic Compound ClassificationInorganic Compound ClassificationTwo main kinds of compoundsTwo main kinds of compounds1. 1. IonicIonic: made up of ions of opposite charge : made up of ions of opposite charge A. strong electrostatic force of attraction; A. strong electrostatic force of attraction; ionic bond ionic bond

B. B. electrons are transferredelectrons are transferred2. 2. CovalentCovalent: made up of two or more nonmetals : made up of two or more nonmetals

A. A. electrons are sharedelectrons are shared

Chemical BondsChemical BondsAtoms bond with each other to become more Atoms bond with each other to become more chemically stable than they were before they chemically stable than they were before they bonded.bonded. To do this their outer electron To do this their outer electron (valence) shell must be complete. (valence) shell must be complete. 1. The 1. The Octet RuleOctet Rule states that atoms will either states that atoms will either gain, lose , or share valence electrons to gain, lose , or share valence electrons to attain “8” electrons in their outer (valence) attain “8” electrons in their outer (valence) shell to become stable.shell to become stable.2. The Noble Gases are the only one group of 2. The Noble Gases are the only one group of elements that are already stable.elements that are already stable.

Naming Binary Ionic CompoundsNaming Binary Ionic CompoundsIons of opposite charge are bonded together. Ions of opposite charge are bonded together. 1. The metal cation (+) is written first and is 1. The metal cation (+) is written first and is named by the metal’s namenamed by the metal’s name2. The nonmetal anion (-) is written second and 2. The nonmetal anion (-) is written second and is named by the nonmetal’s name with a is named by the nonmetal’s name with a revised ending of - ide.revised ending of - ide.

3. Net charge of ions in the compound = 0.3. Net charge of ions in the compound = 0.

4. Subscripts are used to indicate the number 4. Subscripts are used to indicate the number

of ions needed to attain the necessary net of ions needed to attain the necessary net

charge of 0.charge of 0.

Naming Binary Ionic CompoundsNaming Binary Ionic CompoundsNaming Binary Ionic CompoundsNaming Binary Ionic Compounds

Examples of Binary Ionic CompoundsExamples of Binary Ionic CompoundsWhat would the formulas be?What would the formulas be?

1. Sodium chloride1. Sodium chloride

2. Lithium nitride2. Lithium nitride

3. Calcium Fluoride3. Calcium Fluoride

What would the names be?What would the names be?

1. Al1. Al22SS33

2. BaO2. BaO

3. MgBr3. MgBr22

Covalent (Molecular) CompoundsCovalent (Molecular) CompoundsMade up of nonmetalsMade up of nonmetals that that shareshare electrons between atoms. electrons between atoms. 1. This type of bond is called a 1. This type of bond is called a covalent bondcovalent bond. .

Naming Binary Covalent Naming Binary Covalent CompoundsCompounds

1. The first nonmetal’s name is that of the 1. The first nonmetal’s name is that of the

element.element.

2. The second nonmetal’s name has an -ide 2. The second nonmetal’s name has an -ide

ending, just like with ionic compounds.ending, just like with ionic compounds.

3. Use prefixes to describe the subscripts 3. Use prefixes to describe the subscripts

(1 - mono; 2 - di; 3 - tri; 4 - tetra; 5 - penta; (1 - mono; 2 - di; 3 - tri; 4 - tetra; 5 - penta;

6 - hexa; 7- hepta; 8 - octa; 9 - nona; 6 - hexa; 7- hepta; 8 - octa; 9 - nona;

10 - deca)10 - deca)

Examples of Covalent Compounds Examples of Covalent Compounds

PP22OO55 - diphosphorus pentoxide - diphosphorus pentoxide

How would you write the following formulas?How would you write the following formulas?

1. Carbon monoxide1. Carbon monoxide

2. Tetranitrogen decoxide2. Tetranitrogen decoxide

3. Dinitrogen hexoxide3. Dinitrogen hexoxide

Balancing Chemical Equations Balancing Chemical Equations The The Law of Conservation of MatterLaw of Conservation of Matter

1. The mass of the products = the mass of the 1. The mass of the products = the mass of the

reactants (matter is not created or reactants (matter is not created or

destroyed). destroyed).

2. Chemical equations are balanced to ensure 2. Chemical equations are balanced to ensure

that a chemical reaction follows the law of that a chemical reaction follows the law of

conservation of matter. conservation of matter.

Five Balancing Equation Five Balancing Equation Guidelines Guidelines

1. Count the number of atoms of each element 1. Count the number of atoms of each element on both the reactant and the product side.on both the reactant and the product side.2. Use coefficients (the numbers in front of the 2. Use coefficients (the numbers in front of the chemical symbol or formula)chemical symbol or formula)3. Never add or change the subscripts.3. Never add or change the subscripts.4. There are 7 Diatomic elements 4. There are 7 Diatomic elements

(N(N22, O, O22, F, F22, Cl, Cl22, Br, Br22, I, I22,, HH22))

5. Balance the hydrogen atoms and the 5. Balance the hydrogen atoms and the oxygen atoms last.oxygen atoms last.

Balancing Chemical EquationsBalancing Chemical Equations6. A chemical equation uses symbolic language 6. A chemical equation uses symbolic language

to describe a chemical reactionto describe a chemical reaction

7. Equation means equal numbers of atoms of 7. Equation means equal numbers of atoms of

each element on both sides.each element on both sides.

8. Quantities of reactants and products are 8. Quantities of reactants and products are

expressed in moles by using coefficientsexpressed in moles by using coefficients

Balancing Chemical EquationsBalancing Chemical EquationsSymbols for balancing equationsSymbols for balancing equations

(s) – solid; (g) – gas; (l) – liquid(s) – solid; (g) – gas; (l) – liquid

(aq) – aqueous (dissolved in water)(aq) – aqueous (dissolved in water)

Go to Go to www.usaprep.comwww.usaprep.com and practice and practice

balancing equations.balancing equations.

Balancing Chemical EquationsBalancing Chemical EquationsTry these equations:Try these equations:1. H1. H22 + O + O22 H H22OO

2. Ca + Br2. Ca + Br22 CaBr CaBr22

3. Ba(s)3. Ba(s) + O+ O22(g)(g) BaO(s) BaO(s)4. Mg + AuCl3 MgCl2 + Au

Balancing Chemical EquationsBalancing Chemical Equations

The Answers:The Answers:1. 1. 22HH22 + O + O22 22HH22OO

2. Ca + Br2. Ca + Br22 CaBr CaBr22

3. 3. 22Ba(s) + OBa(s) + O22(g)(g) 22BaO(s)BaO(s)4. 33Mg + Mg + 22AuClAuCl33 33MgClMgCl22 + + 22AuAu

Acids and BasesAcids and BasesAcid DefinitionsAcid Definitions::

1. Sour taste1. Sour taste

2. Neutralize the actions of bases2. Neutralize the actions of bases

3. Blue litmus paper turns red3. Blue litmus paper turns red

4. Liberates hydrogen gas when reacted with 4. Liberates hydrogen gas when reacted with

certain metalscertain metals

5. Examples: Foods and drinks5. Examples: Foods and drinks

Acids and BasesAcids and BasesBase DefinitionsBase Definitions::

1. Bitter taste1. Bitter taste

2. Neutralizes the action of acids 2. Neutralizes the action of acids

3. Slippery to the touch3. Slippery to the touch

4. Red litmus paper turns blue4. Red litmus paper turns blue

5. Examples: Cleaning solutions5. Examples: Cleaning solutions

Acids and BasesAcids and BasesAn acid + a base An acid + a base a salt + watera salt + water

Strong acidsStrong acids: : hydrochloric acid, sulfuric acid, nitric acidhydrochloric acid, sulfuric acid, nitric acid

Strong baseStrong base::sodium hydroxidesodium hydroxide

Weak acidWeak acid:: acetic acidacetic acidWeak baseWeak base: :

ammoniaammonia

pH ScalepH ScaleThe pH scale has The pH scale has

values from 0 - 14.values from 0 - 14.

0 - 6 is acidic0 - 6 is acidic

7 is neutral7 is neutral

8 -14 is basic 8 -14 is basic

The MoleThe MoleThe moleThe mole is the SI unit of measure for the is the SI unit of measure for the

amount of a substance.amount of a substance.

1. The mole is a way to measure the mass of 1. The mole is a way to measure the mass of

elements and compounds.elements and compounds.

2. The molar mass of any element is 2. The molar mass of any element is

numerically equal to its atomic mass and has numerically equal to its atomic mass and has

the units of g/mol.the units of g/mol.

3. Example: 3. Example: The mass of one mole of

potassium (K) is 40 grams.

Physical and Chemical ChangesPhysical and Chemical Changes1. 1. Physical ChangePhysical Change - Only the appearance - Only the appearance

changes. The identity is still the same. Some changes. The identity is still the same. Some

of the kinds of changes are: and of the kinds of changes are: and

phase (state).phase (state).

A. size and shape (splitting, breaking, A. size and shape (splitting, breaking,

tearing, or hammering). tearing, or hammering).

B. phase or state (melting, vaporizing, B. phase or state (melting, vaporizing,

freezing, or condensing).freezing, or condensing).

Physical and Chemical ChangesPhysical and Chemical Changes2. 2. Chemical ChangeChemical Change - The appearance and the - The appearance and the identity changes. A new product is formed. identity changes. A new product is formed. The way you know a new product is formed The way you know a new product is formed is by the following: is by the following:

A. gas formed B. color changeA. gas formed B. color change C. mass change D. heat changeC. mass change D. heat change E. solid formed F. light released E. solid formed F. light released

Examples are: rusting, growing, burning, Examples are: rusting, growing, burning, combusting, fermenting, cooking, frying, and combusting, fermenting, cooking, frying, and exploding. exploding.

Nuclear ReactionsNuclear ReactionsA A nuclear reactionnuclear reaction results when an unstable results when an unstable nucleus breaks down and emits radioactive nucleus breaks down and emits radioactive particles.particles.1. There are 3 types of particles released during 1. There are 3 types of particles released during radioactive decay. radioactive decay. A. the A. the alpha particle (alpha particle (αα)) (released during (released during alpha decayalpha decay B. the B. the beta particle (beta particle (ββ)) (released during beta (released during beta decaydecay C. the C. the gamma particle (gamma particle (γγ)) (always released (always released during radioactive decay of any kind. during radioactive decay of any kind.

Three Types of Radioactive DecayThree Types of Radioactive Decay1.1. Alpha decay Alpha decay, alpha particle (helium nucleus , alpha particle (helium nucleus with a + 2 charge) releasedwith a + 2 charge) released A. largest, slowest, least penetrating particleA. largest, slowest, least penetrating particle2.2. Beta decay Beta decay, beta particle (fast moving , beta particle (fast moving electron with a – 1 charge) released electron with a – 1 charge) released A. more penetrating than an alpha particleA. more penetrating than an alpha particle3. 3. Gamma radiationGamma radiation, (no particle, no mass or , (no particle, no mass or charge - a form of energy) releasedcharge - a form of energy) released A. the most penetrating and the most A. the most penetrating and the most damaging (shielded by lead)damaging (shielded by lead)

Half LifeHalf LifeThe half life of a radioactive isotope is the time The half life of a radioactive isotope is the time

it takes for one half of the isotope to decay.it takes for one half of the isotope to decay.

1. Example: The half life of mercury - 195 is 31 1. Example: The half life of mercury - 195 is 31

hours. If you start with 20 g, how much will hours. If you start with 20 g, how much will

be left after be left after

(A) 31 hours? (10 g)(A) 31 hours? (10 g)

(B) 62 hours? (5 g)(B) 62 hours? (5 g)

Particles in an Electric FieldParticles in an Electric Field

Remember the charges for each particle. Also remember that like charges repel and oppositecharges attract.

Nuclear Fission and Nuclear FusionNuclear Fission and Nuclear FusionNuclear FissionNuclear Fission is the splitting of nuclei resulting is the splitting of nuclei resulting

in a tremendous release of energy.in a tremendous release of energy.

Nuclear FusionNuclear Fusion is the combining of nuclei is the combining of nuclei

resulting in an even greater release of energy. resulting in an even greater release of energy.

The sun uses nuclear fusion to produce energy The sun uses nuclear fusion to produce energy

1. 2 hydrogen atoms combine to form 1 helium 1. 2 hydrogen atoms combine to form 1 helium

atom.atom.

Energy/ Heat/ Phase ChangesEnergy/ Heat/ Phase Changes1.1. Temperature Temperature is the measure of the average is the measure of the average

kinetic energy of particles.kinetic energy of particles.

2.2. Heat Heat is a form of Energy that may be is a form of Energy that may be

absorbed or released. Heat flows from a absorbed or released. Heat flows from a

warm body to a cooler one until equilibrium is warm body to a cooler one until equilibrium is

reached.reached.

3. A 3. A caloriecalorie is the amount of heat required to is the amount of heat required to

raise the temperature of one g of water one raise the temperature of one g of water one

degree Celsius. degree Celsius.

Types of Phase ChangesTypes of Phase Changes1. 1. meltingmelting - solid to liquid - solid to liquid

2. 2. freezingfreezing - liquid to solid - liquid to solid

3. 3. evaporationevaporation - liquid to gas - liquid to gas

4. 4. condensationcondensation - gas to liquid - gas to liquid

5. 5. sublimationsublimation - solid to gas - solid to gas

6. 6. depositiondeposition - gas to solid - gas to solid

Key Terms for HeatKey Terms for Heat1. 1. EnergyEnergy - the capacity to do work - the capacity to do work2. 2. HeatHeat - energy transferred from one object to - energy transferred from one object to another (another (The SI unit of heat is the JouleThe SI unit of heat is the Joule (4.18 (4.18 Joules = 1 calorie).Joules = 1 calorie).3. 3. ThermochemistryThermochemistry – the study of heat effects – the study of heat effects in chemical reactionsin chemical reactions4. 4. CombustionCombustion - chemical reactions that - chemical reactions that release heatrelease heat

5. 5. Exothermic reactionExothermic reaction - one that releases heat - one that releases heat

6. 6. Endothermic reactionEndothermic reaction - one that absorbs heat - one that absorbs heat

HeatHeatSpecific heat capacitySpecific heat capacity is the amount of heat is the amount of heat

required to raise the temperature of one gram of required to raise the temperature of one gram of

a substance one degree Celsius. The specific a substance one degree Celsius. The specific

heat capacity of water is 1.heat capacity of water is 1.

1. Water has a high specific heat capacity due 1. Water has a high specific heat capacity due

to hydrogen bonds. This means that it to hydrogen bonds. This means that it

doesn’t change temperature very much doesn’t change temperature very much

despite a large amount of addition and despite a large amount of addition and

subtraction of heat energy. subtraction of heat energy.

2. Metals have low specific heat capacities.2. Metals have low specific heat capacities.

Energy in Chemical Reactions Energy in Chemical Reactions The The bond breakingbond breaking that occurs in reactants that occurs in reactants

during a chemical reaction during a chemical reaction requires energyrequires energy. .

The The bond formationbond formation that occurs in products that occurs in products

during a chemical reaction during a chemical reaction releases energyreleases energy. .

An An endothermicendothermic or or exothermicexothermic reactionreaction is is

determined by the balance between these two determined by the balance between these two

processes.processes.

3 Phases (States) of Matter3 Phases (States) of MatterThe balance between the attractive forces The balance between the attractive forces between the particles and the kinetic energy of between the particles and the kinetic energy of the particles determines the the particles determines the phase of matterphase of matter..1. High KE of the particles and low attractive 1. High KE of the particles and low attractive forces between the particles = gas.forces between the particles = gas.2. Low KE of the particles and high attractive 2. Low KE of the particles and high attractive forces between the particles = solid. forces between the particles = solid. 3. Intermediate KE of the particles and 3. Intermediate KE of the particles and intermediate attractive forces between the intermediate attractive forces between the particles = liquid. particles = liquid.

The Phase Diagram for Water The Phase Diagram for Water

SolidsSolidsThe two main types of solids crystalline solids The two main types of solids crystalline solids

and amorphous solids. and amorphous solids.

1. In a 1. In a crystalline solidcrystalline solid, the atoms, ions, or , the atoms, ions, or

molecules are arranged in an orderly, molecules are arranged in an orderly,

repeating, 3-dimensional pattern (crystal repeating, 3-dimensional pattern (crystal

lattice)lattice)

SolidsSolids2. In an 2. In an amorphous solidamorphous solid, the internal structure , the internal structure

lacks order. Atoms, ions, or molecules are lacks order. Atoms, ions, or molecules are

randomly arranged. randomly arranged.

A. Generally, these substances are cooled A. Generally, these substances are cooled

rapidly. There is not enough time for the rapidly. There is not enough time for the

particles to arrange themselves in a particles to arrange themselves in a

pattern.pattern.

B. Examples: Rubber, glass, plastics, B. Examples: Rubber, glass, plastics,

polymerspolymers

AllotropesAllotropesAllotropesAllotropes are substances with the same are substances with the same elemental composition, but different geometric elemental composition, but different geometric arrangements.arrangements.1. Example, carbon has 4 allotropes: 1. Example, carbon has 4 allotropes:

A. diamond - formed under tremendous A. diamond - formed under tremendous pressure pressure

B. graphite - more loosely packed B. graphite - more loosely packed C. soot - randomly bonded (amorphous C. soot - randomly bonded (amorphous

form)form) D. buckey ballD. buckey ball

Kinetic Molecular Theory of GasesKinetic Molecular Theory of Gases1. Gases are made up of very small particles 1. Gases are made up of very small particles called atoms or molecules.called atoms or molecules.2. Gas particles are separated by large 2. Gas particles are separated by large distances (low density).distances (low density).3. The particles are in constant, random, 3. The particles are in constant, random, straight-line motion undergoing thousands of straight-line motion undergoing thousands of collisions per second.collisions per second.4. Collisions are perfectly elastic - total kinetic 4. Collisions are perfectly elastic - total kinetic energy remains constant.energy remains constant.5. Gases exert a pressure due to the collisions 5. Gases exert a pressure due to the collisions on each other.on each other.

Collision TheoryCollision Theory1. When gas particles collide they exert a 1. When gas particles collide they exert a

pressure on their container.pressure on their container.

2. 2. TemperatureTemperature is the measure of the average is the measure of the average

kinetic energy of the gas particles.kinetic energy of the gas particles.

3. There are 4 main properties of gases that 3. There are 4 main properties of gases that

determine their physical behavior.determine their physical behavior.

Four Main Properties of GasesFour Main Properties of Gases1. 1. PressurePressure = force / area = force / area

2. 2. TemperatureTemperature = the average kinetic energy of = the average kinetic energy of

particlesparticles

3. 3. VolumeVolume = space occupied by matter. = space occupied by matter.

4. 4. Amount of gasAmount of gas is measured in grams or is measured in grams or

moles. moles.

What happens to the volume of a gas if the What happens to the volume of a gas if the pressure is increased at constant temperature?pressure is increased at constant temperature?

What happens to the volume of a gas if the What happens to the volume of a gas if the temperature is increased at constant pressure?temperature is increased at constant pressure?

Lewis Dot Structures Lewis Dot Structures

Rules for Lewis Dot Structures Rules for Lewis Dot Structures 1. Count the total number of dots (valence 1. Count the total number of dots (valence electrons) in the structure.electrons) in the structure.2. Spatially arrange the atoms. (More than two 2. Spatially arrange the atoms. (More than two atoms - locate the central atom)atoms - locate the central atom)3. Try to obtain 8 dots (valence electrons) 3. Try to obtain 8 dots (valence electrons) around each atom (2 dots around hydrogen).around each atom (2 dots around hydrogen).4. If single bonds don’t work, try double bonds, 4. If single bonds don’t work, try double bonds, then triple bonds.then triple bonds.

Lewis Dot StructuresLewis Dot Structures

Three Factors Affecting the Three Factors Affecting the Rate of DissolvingRate of Dissolving

How fast will a solute dissolve in a solvent?How fast will a solute dissolve in a solvent?

1. 1. Stirring or agitationStirring or agitation (more solute / solvent (more solute / solvent

contact at a faster rate)contact at a faster rate)

2. 2. Smaller particlesSmaller particles (increases the surface area (increases the surface area

of the solute, therefore there is more solute / of the solute, therefore there is more solute /

solvent contact at a faster rate)solvent contact at a faster rate)

3. 3. Increasing the temperatureIncreasing the temperature (increases the (increases the

kinetic energy and faster rate of contact kinetic energy and faster rate of contact

between the solute/solvent particles)between the solute/solvent particles)

The Solubility of Solids at The Solubility of Solids at Different Temperatures Different Temperatures

1. What is the solubility 1. What is the solubility

of sugar at 50of sugar at 50ooC?C?

2. Which solute is least2. Which solute is least

affected by an affected by an

increase in temp?increase in temp?

3. Generally, as temp 3. Generally, as temp

increases, increases,

solubility?solubility?

GHSGT Chemistry ReviewGHSGT Chemistry Review

The EndThe End

Types of Measurement Qualitative measurement: uses words to describe something. (i.e. A yellow-green...

Documents

Transcript of Types of Measurement Qualitative measurement: uses words to describe something. (i.e. A yellow-green...