Chemistry      In this science we      study matter and the      changes it      undergoes.                            Mat...
MatterWe define matter as anything that has massand takes up space.                                              Matter   ...
Matter• Atoms are the building blocks of matter.                                                   Matter                 ...
Matter• Atoms are the building blocks of matter.• Each element is made of the same kind of atom.                          ...
Matter• Atoms are the building blocks of matter.• Each element is made of the same kind of atom.• A compound is made of tw...
States of Matter                         Matter                          And                       Measurement            ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Classification of Matter                                 Matter                                  And                      ...
Properties and Changes of    Matter                  Matter                   And                Measurement            © ...
Types of Properties• Physical Properties…  – Can be observed without changing a    substance into another substance.    • ...
Types of Properties• Intensive Properties…  – Are independent of the amount of the    substance that is present.    • Dens...
Types of Changes• Physical Changes  – These are changes in matter that do not    change the composition of a substance.   ...
Chemical ReactionsIn the course of a chemical reaction, thereacting substances are converted to new                       ...
CompoundsCompounds can bebroken down intomore elementalparticles.                            Matter                       ...
Separation of  Mixtures                  Matter                   And                Measurement            © 2009, Prenti...
Filtration        In filtration solid        substances are        separated from liquids        and solutions.           ...
Distillation        Distillation uses        differences in the        boiling points of        substances to        separ...
ChromatographyThis technique separates substances on thebasis of differences in solubility in a solvent.                  ...
What do these countries have        in common?      US, Liberia and Burma                                    Matter       ...
What do these countries have        in common?         US, Liberia and Burma• They use the imperial system                ...
View of Countries using Metric USA          Berma    Liberia                                   Matter                     ...
Units ofMeasurement                Matter                 And              Measurement          © 2009, Prentice-Hall, Inc.
SI Units• Système International d’Unités• A different base unit is used for each quantity.                                ...
Metric SystemPrefixes convert the base units into units thatare appropriate for the item being measured.                  ...
Volume• The most commonly  used metric units for  volume are the liter (L)  and the milliliter (mL).   – A liter is a cube...
Uncertainty inMeasurement                  Matter                   And                Measurement            © 2009, Pren...
Uncertainty in MeasurementsDifferent measuring devices have differentuses and different degrees of accuracy.              ...
Uncertainty in Measurements Different measuring devices have different uses and different degrees of accuracy.1 ml        ...
Uncertainty in MeasurementsDifferent measuring devices have differentuses and different degrees of accuracy.              ...
Accuracy versus Precision• Accuracy refers to the proximity of  a measurement to the true value  of a quantity.• Precision...
Significant Figures• The term significant figures refers to  digits that were measured.• When rounding calculated numbers,...
Significant Figures1. All nonzero digits are significant.2. Zeroes between two significant figures   are themselves signif...
Significant Figures• When addition or subtraction is  performed, answers are rounded to the  least significant decimal pla...
Temperature       By definition       temperature is a       measure of the       average kinetic       energy of the     ...
Temperature      • In scientific        measurements, the        Celsius and Kelvin        scales are most often        us...
Temperature       • The Kelvin is the SI         unit of temperature.       • It is based on the         properties of gas...
Temperature       • The Fahrenheit         scale is not used in         scientific         measurements.       ∀ °F = 9/5(...
DensityDensity is a physical property of a            substance.             m          d=             V                  ...
Dimensional Analysis      • We use dimensional analysis        to convert one quantity to        another.      • Most comm...
Dimensional AnalysisUse the form of the conversion factorthat puts the sought-for unit in thenumerator.                   ...
Dimensional Analysis• For example, to convert 8.00 m to inches,  – convert m to cm  – convert cm to in.             100 cm...
Atomic Theory of MatterThe theory that atoms are the fundamentalbuilding blocks of matter reemerged in the early19th centu...
Daltons PostulatesEach element is composed of extremely smallparticles called atoms.                                      ...
Daltons PostulatesAll atoms of a given element are identical to oneanother in mass (?) and other properties, but theatoms ...
Daltons PostulatesAtoms of an element are notchanged into atoms of a differentelement by chemical reactions;atoms are neit...
Dalton’s PostulatesCompounds are formed when atoms ofmore than one element combine; agiven compound always has the samerel...
Law of Constant Composition                     Joseph Proust (1754–1826)• This is also known as the law of definite  prop...
Law of Conservation of MassThe total mass of substances present atthe end of a chemical process is thesame as the mass of ...
The Electron• Streams of negatively charged particles were  found to emanate from cathode tubes.• J. J. Thompson is credit...
The ElectronThompson measured the charge/mass ratioof the electron to be 1.76 × 108 coulombs/g.                           ...
Millikan Oil Drop ExperimentOnce the charge/massratio of the electronwas known,determination of eitherthe charge or the ma...
Millikan Oil Drop ExperimentRobert Millikan(University of Chicago)determined the chargeon the electron in1909.            ...
Radioactivity• Radioactivity is the spontaneous  emission of radiation by an atom.• It was first observed by Henri  Becque...
Radioactivity• Three types of radiation were discovered by  Ernest Rutherford:    α particles    β particles    γ rays    ...
The Atom, circa 1900         • The prevailing theory           was that of the “plum           pudding” model, put        ...
Discovery of the Nucleus             Ernest Rutherford             shot α particles at a             thin sheet of gold fo...
The Nuclear AtomSince some particleswere deflected atlarge angles,Thompson’s modelcould not be correct.                   ...
The Nuclear Atom• Rutherford postulated a very small,  dense nucleus with the electrons  around the outside of the atom.• ...
Other Subatomic Particles• Protons were discovered by Rutherford  in 1919.• Neutrons were discovered by James  Chadwick in...
Subatomic Particles• Protons and electrons are the only particles that  have a charge.• Protons and neutrons have essentia...
Symbols of ElementsElements are symbolized by one or twoletters.                                              Matter      ...
Atomic NumberAll atoms of the same element have the samenumber of protons:The atomic number (Z)                           ...
Atomic MassThe mass of an atom in atomic mass units(amu) is the total number of protons andneutrons in the atom.          ...
Isotopes• Isotopes are atoms of the same element with  different masses.• Isotopes have different numbers of neutrons.  11...
Atomic Mass        Atomic and        molecular masses        can be measured        with great accuracy        with a mass...
Average Mass• Because in the real world we use large  amounts of atoms and molecules, we  use average masses in calculatio...
Periodic Table          • It is a systematic            catalog of the            elements.          • Elements are       ...
PeriodicityWhen one looks at the chemical properties ofelements, one notices a repeating pattern ofreactivities.          ...
Periodic Table• The rows on the  periodic chart are  periods.• Columns are groups.• Elements in the same  group have simil...
GroupsThese five groups are known by their names.                                              Matter                     ...
Periodic Table                 Nonmetals are                 on the right                 side of the                 peri...
Periodic Table                 Metalloids                 border the                 stair-step line                 (with...
Periodic Table                 Metals are                 on the left                 side of the                 chart.  ...
Chemical Formulas      The subscript to the right      of the symbol of an      element tells the number      of atoms of ...
Chemical Formulas      Molecular compounds      are composed of      molecules and almost      always contain only      no...
Diatomic MoleculesThese seven elements occur naturally asmolecules containing two atoms.                                  ...
Types of Formulas• Empirical formulas give the lowest  whole-number ratio of atoms of each  element in a compound.• Molecu...
Types of Formulas    • Structural formulas show the      order in which atoms are      bonded.    • Perspective drawings a...
Ions• When atoms lose or gain electrons, they  become ions.  – Cations are positive and are formed by elements    on the l...
Ionic BondsIonic compounds (such as NaCl) aregenerally formed between metals andnonmetals.                                ...
Writing Formulas• Because compounds are electrically neutral,  one can determine the formula of a  compound this way:  – T...
Common Cations                       Matter                        And                     Measurement                 © 2...
Common Anions                      Matter                       And                    Measurement                © 2009, ...
Inorganic Nomenclature• Write the name of the cation.• If the anion is an element, change its  ending to -ide; if the anio...
Patterns in Oxyanion Nomenclature  • When there are two oxyanions involving    the same element:    – The one with fewer o...
Patterns in Oxyanion                Nomenclature• The one with the second fewest oxygens ends in -ite.     – ClO2− : chlor...
Patterns in Oxyanion Nomenclature• The one with the fewest oxygens has the prefix hypo-  and ends in -ite.     – ClO− : hy...
Acid Nomenclature         • If the anion in the acid           ends in -ide, change           the ending to -ic acid      ...
Acid Nomenclature         • If the anion in the acid           ends in -ite, change           the ending to -ous          ...
Acid Nomenclature         • If the anion in the acid           ends in -ate, change           the ending to -ic acid.     ...
Nomenclature of Binary    Compounds          • The less electronegative            atom is usually listed first.          ...
Nomenclature of Binary    Compounds          • The ending on the more            electronegative element            is cha...
Nomenclature of Binary    Compounds          • If the prefix ends with a            or o and the name of the            el...
Nomenclature of Organic        Compounds• Organic chemistry is the study of carbon.• Organic chemistry has its own system ...
Nomenclature of Organic      CompoundsThe simplest hydrocarbons (compoundscontaining only carbon and hydrogen) arealkanes....
Nomenclature of Organic      CompoundsThe first part of the names above correspondto the number of carbons (meth- = 1, eth...
Nomenclature of Organic           Compounds• When a hydrogen in an alkane is replaced with  something else (a functional g...
Law of Conservation of Mass              “We may lay it down as an          incontestable axiom that, in all        the op...
Chemical EquationsChemical equations are conciserepresentations of chemical reactions.                                    ...
Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g)   CO2 (g) + 2 H2O (g)                                         Matter     ...
Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g)             CO2 (g) + 2 H2O (g)Reactants appear on the leftside of the eq...
Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g)            CO2 (g) + 2 H2O (g)Products appear on theright side of the equ...
Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g)           CO2 (g) + 2 H2O (g)The states of the reactants and productsare ...
Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g)           CO2 (g) + 2 H2O (g) Coefficients are inserted to balance the eq...
Subscripts and Coefficients       Give Different Information• Subscripts tell the number of atoms of  each element in a mo...
Subscripts and Coefficients       Give Different Information• Subscripts tell the number of atoms of  each element in a mo...
Reaction Types                 Matter                  And               Measurement           © 2009, Prentice-Hall, Inc.
Combination Reactions                                         • In this type of                                           ...
Decomposition Reactions                                   • In a decomposition                                     one sub...
Combustion Reactions                                     • These are generally                                       rapid...
FormulaWeights                Matter                 And              Measurement          © 2009, Prentice-Hall, Inc.
Formula Weight (FW)• A formula weight is the sum of the  atomic weights for the atoms in a  chemical formula.• So, the for...
Molecular Weight (MW)• A molecular weight is the sum of the  atomic weights of the atoms in a  molecule.• For the molecule...
Percent Composition   One can find the percentage of the   mass of a compound that comes from   each of the elements in th...
Percent CompositionSo the percentage of carbon in ethaneis…                (2)(12.0 amu)         %C =                (30.0...
Moles              Matter               And            Measurement        © 2009, Prentice-Hall, Inc.
Avogadro’s Number• 6.02 x 1023• 1 mole of 12C has a  mass of 12 g.                                 Matter                 ...
Molar Mass• By definition, a molar mass is the mass  of 1 mol of a substance (i.e., g/mol).  – The molar mass of an elemen...
Using MolesMoles provide a bridge from the molecularscale to the real-world scale.                                        ...
Mole Relationships• One mole of atoms, ions, or molecules contains  Avogadro’s number of those particles.• One mole of mol...
FindingEmpiricalFormulas                  Matter                   And                Measurement            © 2009, Prent...
Calculating Empirical          FormulasOne can calculate the empirical formula fromthe percent composition.               ...
Calculating Empirical             FormulasThe compound para-aminobenzoic acid (you may haveseen it listed as PABA on your ...
Calculating Empirical           FormulasAssuming 100.00 g of para-aminobenzoic acid,      C:    61.31 g x  1 mol    = 5.10...
Calculating Empirical                FormulasCalculate the mole ratio by dividing by the smallest numberof moles:         ...
Calculating Empirical             FormulasThese are the subscripts for the empirical formula:     C7H7NO2                 ...
Combustion Analysis• Compounds containing C, H and O are routinely  analyzed through combustion in a chamber like this.  –...
Elemental Analyses             Compounds             containing other             elements are             analyzed using ...
Stoichiometric CalculationsThe coefficients in the balanced equation givethe ratio of moles of reactants and products.    ...
Stoichiometric CalculationsStarting with themass of SubstanceA you can use theratio of thecoefficients of A andB to calcul...
Stoichiometric Calculations           C6H12O6 + 6 O2 → 6 CO2 + 6 H2OStarting with 1.00 g of C6H12O6…we calculate the moles...
LimitingReactants                  Matter                   And                Measurement            © 2009, Prentice-Hal...
How Many Cookies Can I       Make?           • You can make cookies             until you run out of one             of th...
How Many Cookies Can I       Make?           • In this example the             sugar would be the             limiting rea...
Limiting Reactants• The limiting reactant is the reactant present in  the smallest stoichiometric amount.   – In other wor...
Limiting ReactantsIn the example below, the O2 would be theexcess reagent.                                                ...
Theoretical Yield• The theoretical yield is the maximum  amount of product that can be made.  – In other words it’s the am...
Percent Yield   One finds the percent yield by   comparing the amount actually obtained   (actual yield) to the amount it ...
Solutions   • Solutions are defined as     homogeneous mixtures     of two or more pure     substances.   • The solvent is...
Dissociation      • When an ionic        substance dissolves        in water, the solvent        pulls the individual     ...
Dissociation      • An electrolyte is a        substances that        dissociates into ions        when dissolved in      ...
Electrolytes      • An electrolyte is a        substances that        dissociates into ions        when dissolved in      ...
Electrolytes andNonelectrolytes            Soluble ionic            compounds tend            to be electrolytes.         ...
Electrolytes andNonelectrolytes          Molecular          compounds tend to          be nonelectrolytes,          except...
Electrolytes• A strong electrolyte  dissociates completely  when dissolved in  water.• A weak electrolyte  only dissociate...
Strong Electrolytes Are…• Strong acids• Strong bases                                    Matter                            ...
Strong Electrolytes Are…• Strong acids• Strong bases• Soluble ionic salts                                     Matter      ...
Precipitation ReactionsWhen one mixes ionsthat form compoundsthat are insoluble (ascould be predicted bythe solubilityguid...
Metathesis (Exchange) Reactions • Metathesis comes from a Greek word that   means “to transpose.”    AgNO3 (aq) + KCl (aq)...
Metathesis (Exchange) Reactions • Metathesis comes from a Greek word that   means “to transpose.” • It appears the ions in...
Solubility of different compounds       (NS = non soluble in water, S = soluble in water)              Cl-    Br-     I-  ...
Solution Chemistry• It is helpful to pay attention to exactly  what species are present in a reaction  mixture (i.e., soli...
Molecular EquationThe molecular equation lists the reactantsand products in their molecular form.AgNO3 (aq) + KCl (aq) → ...
Ionic Equation• In the ionic equation all strong electrolytes (strong  acids, strong bases, and soluble ionic salts) are  ...
Net Ionic Equation• To form the net ionic equation, cross out anything  that does not change from the left side of the  eq...
Net Ionic Equation• To form the net ionic equation, cross out anything  that does not change from the left side of the  eq...
Net Ionic Equation• To form the net ionic equation, cross out anything  that does not change from the left side of the  eq...
Writing Net Ionic Equations1. Write a balanced molecular equation.2. Dissociate all strong electrolytes.3. Cross out anyth...
Acids   • Arrhenius defined acids     as substances that     increase the     concentration of H+ when     dissolved in wa...
Acids    There are only seven    strong acids:    • Hydrochloric (HCl)    • Hydrobromic (HBr)    • Hydroiodic (HI)    • Ni...
Bases• Arrhenius defined bases  as substances that  increase the  concentration of OH−  when dissolved in water.• Brønsted...
BasesThe strong basesare the solublemetal salts ofhydroxide ion:•   Alkali metals•   Calcium•   Strontium•   Barium       ...
Acid-Base Reactions           In an acid-base           reaction, the acid           donates a proton           (H+) to th...
Neutralization Reactions Generally, when solutions of an acid and a base are combined, the products are a salt and water.C...
Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is…    HCl (aq) + NaOH (aq) →...
Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is…    HCl (aq) + NaOH (aq) →...
Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is…    HCl (aq) + NaOH (aq) →...
Gas-Forming Reactions  • Some metathesis reactions do not give the    product expected.  • In this reaction, the expected ...
Gas-Forming Reactions     When a carbonate or bicarbonate reacts with     an acid, the products are a salt, carbon     dio...
Gas-Forming Reactions   Similarly, when a sulfite reacts with an acid,   the products are a salt, sulfur dioxide, and   wa...
Gas-Forming Reactions• This reaction gives the predicted product, but  you had better carry it out in the hood, or you  wi...
Oxidation-Reduction Reactions• An oxidation occurs  when an atom or ion  loses electrons.• A reduction occurs  when an ato...
Oxidation NumbersTo determine if an oxidation-reductionreaction has occurred, we assign anoxidation number to each element...
Oxidation Numbers• Elements in their elemental form have  an oxidation number of 0.• The oxidation number of a monatomic  ...
Oxidation Numbers• Nonmetals tend to have negative  oxidation numbers, although some are  positive in certain compounds or...
Oxidation Numbers• Nonmetals tend to have negative  oxidation numbers, although some are  positive in certain compounds or...
Oxidation Numbers• The sum of the oxidation numbers in a  neutral compound is 0.• The sum of the oxidation numbers in a  p...
Displacement Reactions      • In displacement reactions,        ions oxidize an element.      • The ions, then, are       ...
Displacement Reactions  In this reaction,  silver ions oxidize  copper metal.Cu (s) + 2 Ag+ (aq) → Cu2+ (aq) + 2 Ag (s)  ...
Displacement Reactions  The reverse reaction,  however, does not  occur.                      xCu2+ (aq) + 2 Ag (s) → Cu ...
Activity Series                        Matter                         And                      Measurement                ...
Molarity• Two solutions can contain the same  compounds but be quite different because the  proportions of those compounds...
Mixing a Solution      • To create a solution of a        known molarity, one        weighs out a known mass        (and, ...
Dilution• One can also dilute a more concentrated  solution by  – Using a pipet to deliver a volume of the solution to    ...
DilutionThe molarity of the new solution can be determinedfrom the equation                   Mc × Vc = Md × Vd,where Mc a...
Using Molarities inStoichiometric Calculations                                Matter                                 And  ...
Titration            Titration is an            analytical            technique in            which one can            cal...
Chemistry, The Central Science, 11th edition           Theodore L. Brown; H. Eugene LeMay, Jr.;                     and Br...
Energy• Energy is the ability to do work or  transfer heat.  – Energy used to cause an object that has    mass to move is ...
Potential EnergyPotential energy is energy an objectpossesses by virtue of its position or chemicalcomposition.           ...
Kinetic EnergyKinetic energy is energy an object possessesby virtue of its motion.                        1               ...
Units of Energy• The SI unit of energy is the joule (J).                       kg m2               1 J = 1              ...
Definitions:System and Surroundings          • The system includes the            molecules we want to            study (h...
Definitions: Work• Energy used to  move an object over  some distance is  work.• w=F×d  where w is work, F  is the force, ...
Heat  • Energy can also be    transferred as heat.  • Heat flows from    warmer objects to    cooler objects.             ...
Conversion of Energy• Energy can be converted from one type to  another.• For example, the cyclist above has potential  en...
Conversion of Energy• As she coasts down the hill, her potential  energy is converted to kinetic energy.• At the bottom, a...
First Law of Thermodynamics• Energy is neither created nor destroyed.• In other words, the total energy of the universe is...
Internal EnergyThe internal energy of a system is the sum of allkinetic and potential energies of all componentsof the sys...
Internal EnergyBy definition, the change in internal energy, ∆E,is the final energy of the system minus the initialenergy ...
Changes in Internal Energy            • If ∆E > 0, Efinal > Einitial               – Therefore, the system                ...
Changes in Internal Energy            • If ∆E < 0, Efinal < Einitial               – Therefore, the system                ...
Changes in Internal Energy             • When energy is               exchanged between               the system and the  ...
∆E, q, w, and Their Signs                                   Matter                                    And                 ...
Exchange of Heat between  System and Surroundings• When heat is absorbed by the system from  the surroundings, the process...
Exchange of Heat between  System and Surroundings• When heat is absorbed by the system from  the surroundings, the process...
State FunctionsUsually we have no way of knowing theinternal energy of a system; finding that valueis simply too complex a...
State Functions• However, we do know that the internal energy  of a system is independent of the path by  which the system...
State Functions• Therefore, internal energy is a state function.• It depends only on the present state of the  system, not...
State Functions        • However, q and w are          not state functions.        • Whether the battery is          short...
Work   Usually in an open   container the only work   done is by a gas   pushing on the   surroundings (or by the   surrou...
WorkWe can measure the work done by the gas ifthe reaction is done in a vessel that has beenfitted with a piston.         ...
Enthalpy• If a process takes place at constant  pressure (as the majority of processes we  study do) and the only work don...
Enthalpy• When the system changes at constant  pressure, the change in enthalpy, ∆H, is               ∆H = ∆(E + PV)• This...
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Chpt1 11
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  • Figure 2.1 John Dalton (1766-1844)
  • Figure 2.1 John Dalton (1766-1844)
  • Figure 2.1 John Dalton (1766-1844)
  • Figure 2.1 John Dalton (1766-1844)
  • Figure 2.4
  • Figure 2.4
  • Figure 2.5
  • Figure 2.5
  • Figure 2.8
  • Figure 2.9
  • Figure 2.10
  • Figure 2.11
  • Figure 2.12
  • Table 2.1
  • Figure 2.13
  • Chpt1 11

    1. 1. Chemistry In this science we study matter and the changes it undergoes. Matter And Measurement © 2009, Prentice-Hall, Inc.
    2. 2. MatterWe define matter as anything that has massand takes up space. Matter And Measurement © 2009, Prentice-Hall, Inc.
    3. 3. Matter• Atoms are the building blocks of matter. Matter And Measurement © 2009, Prentice-Hall, Inc.
    4. 4. Matter• Atoms are the building blocks of matter.• Each element is made of the same kind of atom. Matter And Measurement © 2009, Prentice-Hall, Inc.
    5. 5. Matter• Atoms are the building blocks of matter.• Each element is made of the same kind of atom.• A compound is made of two or more different kinds of elements. Matter And Measurement © 2009, Prentice-Hall, Inc.
    6. 6. States of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    7. 7. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    8. 8. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    9. 9. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    10. 10. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    11. 11. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    12. 12. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    13. 13. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    14. 14. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    15. 15. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    16. 16. Classification of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    17. 17. Properties and Changes of Matter Matter And Measurement © 2009, Prentice-Hall, Inc.
    18. 18. Types of Properties• Physical Properties… – Can be observed without changing a substance into another substance. • Boiling point, density, mass, volume, etc.• Chemical Properties… – Can only be observed when a substance is changed into another substance. • Flammability, corrosiveness, reactivity with acid, etc. Matter And Measurement © 2009, Prentice-Hall, Inc.
    19. 19. Types of Properties• Intensive Properties… – Are independent of the amount of the substance that is present. • Density, boiling point, color, etc.• Extensive Properties… – Depend upon the amount of the substance present. • Mass, volume, energy, etc. Matter And Measurement © 2009, Prentice-Hall, Inc.
    20. 20. Types of Changes• Physical Changes – These are changes in matter that do not change the composition of a substance. • Changes of state, temperature, volume, etc.• Chemical Changes – Chemical changes result in new substances. • Combustion, oxidation, decomposition, etc. Matter And Measurement © 2009, Prentice-Hall, Inc.
    21. 21. Chemical ReactionsIn the course of a chemical reaction, thereacting substances are converted to new Mattersubstances. And Measurement © 2009, Prentice-Hall, Inc.
    22. 22. CompoundsCompounds can bebroken down intomore elementalparticles. Matter And Measurement © 2009, Prentice-Hall, Inc.
    23. 23. Separation of Mixtures Matter And Measurement © 2009, Prentice-Hall, Inc.
    24. 24. Filtration In filtration solid substances are separated from liquids and solutions. Matter And Measurement © 2009, Prentice-Hall, Inc.
    25. 25. Distillation Distillation uses differences in the boiling points of substances to separate a homogeneous mixture into its components. Matter And Measurement © 2009, Prentice-Hall, Inc.
    26. 26. ChromatographyThis technique separates substances on thebasis of differences in solubility in a solvent. Matter And Measurement © 2009, Prentice-Hall, Inc.
    27. 27. What do these countries have in common? US, Liberia and Burma Matter And Measurement © 2009, Prentice-Hall, Inc.
    28. 28. What do these countries have in common? US, Liberia and Burma• They use the imperial system Matter And Measurement © 2009, Prentice-Hall, Inc.
    29. 29. View of Countries using Metric USA Berma Liberia Matter And Measurement © 2009, Prentice-Hall, Inc.
    30. 30. Units ofMeasurement Matter And Measurement © 2009, Prentice-Hall, Inc.
    31. 31. SI Units• Système International d’Unités• A different base unit is used for each quantity. Matter And Measurement © 2009, Prentice-Hall, Inc.
    32. 32. Metric SystemPrefixes convert the base units into units thatare appropriate for the item being measured. Matter And Measurement © 2009, Prentice-Hall, Inc.
    33. 33. Volume• The most commonly used metric units for volume are the liter (L) and the milliliter (mL). – A liter is a cube 1 dm long on each side. – A milliliter is a cube 1 cm long on each side. Matter And Measurement © 2009, Prentice-Hall, Inc.
    34. 34. Uncertainty inMeasurement Matter And Measurement © 2009, Prentice-Hall, Inc.
    35. 35. Uncertainty in MeasurementsDifferent measuring devices have differentuses and different degrees of accuracy. Matter And Measurement © 2009, Prentice-Hall, Inc.
    36. 36. Uncertainty in Measurements Different measuring devices have different uses and different degrees of accuracy.1 ml Matter And Measurement © 2009, Prentice-Hall, Inc.
    37. 37. Uncertainty in MeasurementsDifferent measuring devices have differentuses and different degrees of accuracy. 0.1 ml Matter And Measurement © 2009, Prentice-Hall, Inc.
    38. 38. Accuracy versus Precision• Accuracy refers to the proximity of a measurement to the true value of a quantity.• Precision refers to the proximity of several measurements to each other. Matter And Measurement © 2009, Prentice-Hall, Inc.
    39. 39. Significant Figures• The term significant figures refers to digits that were measured.• When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers. Matter And Measurement © 2009, Prentice-Hall, Inc.
    40. 40. Significant Figures1. All nonzero digits are significant.2. Zeroes between two significant figures are themselves significant.3. Zeroes at the beginning of a number are never significant.4. Zeroes at the end of a number are significant if a decimal point is written in the number. Matter And Measurement © 2009, Prentice-Hall, Inc.
    41. 41. Significant Figures• When addition or subtraction is performed, answers are rounded to the least significant decimal place.• When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation. Matter And Measurement © 2009, Prentice-Hall, Inc.
    42. 42. Temperature By definition temperature is a measure of the average kinetic energy of the particles in a sample. Matter And Measurement © 2009, Prentice-Hall, Inc.
    43. 43. Temperature • In scientific measurements, the Celsius and Kelvin scales are most often used. • The Celsius scale is based on the properties of water. – 0°C is the freezing point of water. – 100°C is the boiling point of water. Matter And Measurement © 2009, Prentice-Hall, Inc.
    44. 44. Temperature • The Kelvin is the SI unit of temperature. • It is based on the properties of gases. • There are no negative Kelvin temperatures. • K = °C + 273.15 Matter And Measurement © 2009, Prentice-Hall, Inc.
    45. 45. Temperature • The Fahrenheit scale is not used in scientific measurements. ∀ °F = 9/5(°C) + 32 ∀ °C = 5/9(°F − 32) Matter And Measurement © 2009, Prentice-Hall, Inc.
    46. 46. DensityDensity is a physical property of a substance. m d= V Matter And Measurement © 2009, Prentice-Hall, Inc.
    47. 47. Dimensional Analysis • We use dimensional analysis to convert one quantity to another. • Most commonly dimensional analysis utilizes conversion factors (e.g., 1 in. = 2.54 cm) 1 in. 2.54 cm or 2.54 cm 1 in. Matter And Measurement © 2009, Prentice-Hall, Inc.
    48. 48. Dimensional AnalysisUse the form of the conversion factorthat puts the sought-for unit in thenumerator. desired unit Given unit × = desired unit given unitConversion factor Matter And Measurement © 2009, Prentice-Hall, Inc.
    49. 49. Dimensional Analysis• For example, to convert 8.00 m to inches, – convert m to cm – convert cm to in. 100 cm 1 in. 8.00 m × × = 315 in. 1m 2.54 cm Matter And Measurement © 2009, Prentice-Hall, Inc.
    50. 50. Atomic Theory of MatterThe theory that atoms are the fundamentalbuilding blocks of matter reemerged in the early19th century, championed by John Dalton. Matter And Measurement © 2009, Prentice-Hall, Inc.
    51. 51. Daltons PostulatesEach element is composed of extremely smallparticles called atoms. Matter And Measurement © 2009, Prentice-Hall, Inc.
    52. 52. Daltons PostulatesAll atoms of a given element are identical to oneanother in mass (?) and other properties, but theatoms of one element are different from theatoms of all other elements. Matter And Measurement © 2009, Prentice-Hall, Inc.
    53. 53. Daltons PostulatesAtoms of an element are notchanged into atoms of a differentelement by chemical reactions;atoms are neither created nordestroyed in chemical reactions. Matter And Measurement © 2009, Prentice-Hall, Inc.
    54. 54. Dalton’s PostulatesCompounds are formed when atoms ofmore than one element combine; agiven compound always has the samerelative number and kind of atoms. Matter And Measurement © 2009, Prentice-Hall, Inc.
    55. 55. Law of Constant Composition Joseph Proust (1754–1826)• This is also known as the law of definite proportions.• It states that the elemental composition of a pure substance never varies. Matter And Measurement © 2009, Prentice-Hall, Inc.
    56. 56. Law of Conservation of MassThe total mass of substances present atthe end of a chemical process is thesame as the mass of substancespresent before the process took place. Matter And Measurement © 2009, Prentice-Hall, Inc.
    57. 57. The Electron• Streams of negatively charged particles were found to emanate from cathode tubes.• J. J. Thompson is credited with their discovery (1897). Matter And Measurement © 2009, Prentice-Hall, Inc.
    58. 58. The ElectronThompson measured the charge/mass ratioof the electron to be 1.76 × 108 coulombs/g. Matter And Measurement © 2009, Prentice-Hall, Inc.
    59. 59. Millikan Oil Drop ExperimentOnce the charge/massratio of the electronwas known,determination of eitherthe charge or the massof an electron wouldyield the other. Matter And Measurement © 2009, Prentice-Hall, Inc.
    60. 60. Millikan Oil Drop ExperimentRobert Millikan(University of Chicago)determined the chargeon the electron in1909. Matter And Measurement © 2009, Prentice-Hall, Inc.
    61. 61. Radioactivity• Radioactivity is the spontaneous emission of radiation by an atom.• It was first observed by Henri Becquerel.• Marie and Pierre Curie also studied it. Matter And Measurement © 2009, Prentice-Hall, Inc.
    62. 62. Radioactivity• Three types of radiation were discovered by Ernest Rutherford: α particles β particles γ rays Matter And Measurement © 2009, Prentice-Hall, Inc.
    63. 63. The Atom, circa 1900 • The prevailing theory was that of the “plum pudding” model, put forward by Thompson. • It featured a positive sphere of matter with negative electrons imbedded in it. Matter And Measurement © 2009, Prentice-Hall, Inc.
    64. 64. Discovery of the Nucleus Ernest Rutherford shot α particles at a thin sheet of gold foil and observed the pattern of scatter of the particles. Matter And Measurement © 2009, Prentice-Hall, Inc.
    65. 65. The Nuclear AtomSince some particleswere deflected atlarge angles,Thompson’s modelcould not be correct. Matter And Measurement © 2009, Prentice-Hall, Inc.
    66. 66. The Nuclear Atom• Rutherford postulated a very small, dense nucleus with the electrons around the outside of the atom.• Most of the volume of the atom is empty space. Matter And Measurement © 2009, Prentice-Hall, Inc.
    67. 67. Other Subatomic Particles• Protons were discovered by Rutherford in 1919.• Neutrons were discovered by James Chadwick in 1932. Matter And Measurement © 2009, Prentice-Hall, Inc.
    68. 68. Subatomic Particles• Protons and electrons are the only particles that have a charge.• Protons and neutrons have essentially the same mass.• The mass of an electron is so small we ignore it. Matter And Measurement © 2009, Prentice-Hall, Inc.
    69. 69. Symbols of ElementsElements are symbolized by one or twoletters. Matter And Measurement © 2009, Prentice-Hall, Inc.
    70. 70. Atomic NumberAll atoms of the same element have the samenumber of protons:The atomic number (Z) Matter And Measurement © 2009, Prentice-Hall, Inc.
    71. 71. Atomic MassThe mass of an atom in atomic mass units(amu) is the total number of protons andneutrons in the atom. Matter And Measurement © 2009, Prentice-Hall, Inc.
    72. 72. Isotopes• Isotopes are atoms of the same element with different masses.• Isotopes have different numbers of neutrons. 11 12 13 14 6 C 6 C 6 C 6 C Matter And Measurement © 2009, Prentice-Hall, Inc.
    73. 73. Atomic Mass Atomic and molecular masses can be measured with great accuracy with a mass spectrometer. Matter And Measurement © 2009, Prentice-Hall, Inc.
    74. 74. Average Mass• Because in the real world we use large amounts of atoms and molecules, we use average masses in calculations.• Average mass is calculated from the isotopes of an element weighted by their relative abundances. Matter And Measurement © 2009, Prentice-Hall, Inc.
    75. 75. Periodic Table • It is a systematic catalog of the elements. • Elements are arranged in order of atomic number. Matter And Measurement © 2009, Prentice-Hall, Inc.
    76. 76. PeriodicityWhen one looks at the chemical properties ofelements, one notices a repeating pattern ofreactivities. Matter And Measurement © 2009, Prentice-Hall, Inc.
    77. 77. Periodic Table• The rows on the periodic chart are periods.• Columns are groups.• Elements in the same group have similar chemical properties. Matter And Measurement © 2009, Prentice-Hall, Inc.
    78. 78. GroupsThese five groups are known by their names. Matter And Measurement © 2009, Prentice-Hall, Inc.
    79. 79. Periodic Table Nonmetals are on the right side of the periodic table (with the exception of H). Matter And Measurement © 2009, Prentice-Hall, Inc.
    80. 80. Periodic Table Metalloids border the stair-step line (with the exception of Al, Po, and At). Matter And Measurement © 2009, Prentice-Hall, Inc.
    81. 81. Periodic Table Metals are on the left side of the chart. Matter And Measurement © 2009, Prentice-Hall, Inc.
    82. 82. Chemical Formulas The subscript to the right of the symbol of an element tells the number of atoms of that element in one molecule of the compound. Matter And Measurement © 2009, Prentice-Hall, Inc.
    83. 83. Chemical Formulas Molecular compounds are composed of molecules and almost always contain only nonmetals. Matter And Measurement © 2009, Prentice-Hall, Inc.
    84. 84. Diatomic MoleculesThese seven elements occur naturally asmolecules containing two atoms. Matter And Measurement © 2009, Prentice-Hall, Inc.
    85. 85. Types of Formulas• Empirical formulas give the lowest whole-number ratio of atoms of each element in a compound.• Molecular formulas give the exact number of atoms of each element in a compound. Matter And Measurement © 2009, Prentice-Hall, Inc.
    86. 86. Types of Formulas • Structural formulas show the order in which atoms are bonded. • Perspective drawings also show the three-dimensional array of atoms in a compound. Matter And Measurement © 2009, Prentice-Hall, Inc.
    87. 87. Ions• When atoms lose or gain electrons, they become ions. – Cations are positive and are formed by elements on the left side of the periodic chart. – Anions are negative and are formed by elements Matter on the right side of the periodic chart. And Measurement © 2009, Prentice-Hall, Inc.
    88. 88. Ionic BondsIonic compounds (such as NaCl) aregenerally formed between metals andnonmetals. Matter And Measurement © 2009, Prentice-Hall, Inc.
    89. 89. Writing Formulas• Because compounds are electrically neutral, one can determine the formula of a compound this way: – The charge on the cation becomes the subscript on the anion. – The charge on the anion becomes the subscript on the cation. – If these subscripts are not in the lowest whole- number ratio, divide them by the greatest common Matter factor. And Measurement © 2009, Prentice-Hall, Inc.
    90. 90. Common Cations Matter And Measurement © 2009, Prentice-Hall, Inc.
    91. 91. Common Anions Matter And Measurement © 2009, Prentice-Hall, Inc.
    92. 92. Inorganic Nomenclature• Write the name of the cation.• If the anion is an element, change its ending to -ide; if the anion is a polyatomic ion, simply write the name of the polyatomic ion.• If the cation can have more than one possible charge, write the charge as a Roman numeral in parentheses. Matter And Measurement © 2009, Prentice-Hall, Inc.
    93. 93. Patterns in Oxyanion Nomenclature • When there are two oxyanions involving the same element: – The one with fewer oxygens ends in -ite. • NO2− : nitrite; SO32− : sulfite – The one with more oxygens ends in -ate. • NO3− : nitrate; SO42− : sulfate Matter And Measurement © 2009, Prentice-Hall, Inc.
    94. 94. Patterns in Oxyanion Nomenclature• The one with the second fewest oxygens ends in -ite. – ClO2− : chlorite• The one with the second most oxygens ends in -ate. – ClO3− : chlorate Matter And Measurement © 2009, Prentice-Hall, Inc.
    95. 95. Patterns in Oxyanion Nomenclature• The one with the fewest oxygens has the prefix hypo- and ends in -ite. – ClO− : hypochlorite• The one with the most oxygens has the prefix per- and ends in -ate. – ClO4− : perchlorate Matter And Measurement © 2009, Prentice-Hall, Inc.
    96. 96. Acid Nomenclature • If the anion in the acid ends in -ide, change the ending to -ic acid and add the prefix hydro- . – HCl: hydrochloric acid – HBr: hydrobromic acid – HI: hydroiodic acid Matter And Measurement © 2009, Prentice-Hall, Inc.
    97. 97. Acid Nomenclature • If the anion in the acid ends in -ite, change the ending to -ous acid. – HClO: hypochlorous acid – HClO2: chlorous acid Matter And Measurement © 2009, Prentice-Hall, Inc.
    98. 98. Acid Nomenclature • If the anion in the acid ends in -ate, change the ending to -ic acid. – HClO3: chloric acid – HClO4: perchloric acid Matter And Measurement © 2009, Prentice-Hall, Inc.
    99. 99. Nomenclature of Binary Compounds • The less electronegative atom is usually listed first. • A prefix is used to denote the number of atoms of each element in the compound (mono- is not used on the first element listed, however) . Matter And Measurement © 2009, Prentice-Hall, Inc.
    100. 100. Nomenclature of Binary Compounds • The ending on the more electronegative element is changed to -ide. – CO2: carbon dioxide – CCl4: carbon tetrachloride Matter And Measurement © 2009, Prentice-Hall, Inc.
    101. 101. Nomenclature of Binary Compounds • If the prefix ends with a or o and the name of the element begins with a vowel, the two successive vowels are often elided into one. N2O5: dinitrogen pentoxide Matter And Measurement © 2009, Prentice-Hall, Inc.
    102. 102. Nomenclature of Organic Compounds• Organic chemistry is the study of carbon.• Organic chemistry has its own system of nomenclature. Matter And Measurement © 2009, Prentice-Hall, Inc.
    103. 103. Nomenclature of Organic CompoundsThe simplest hydrocarbons (compoundscontaining only carbon and hydrogen) arealkanes. Matter And Measurement © 2009, Prentice-Hall, Inc.
    104. 104. Nomenclature of Organic CompoundsThe first part of the names above correspondto the number of carbons (meth- = 1, eth- = 2,prop- = 3, etc.). Matter And Measurement © 2009, Prentice-Hall, Inc.
    105. 105. Nomenclature of Organic Compounds• When a hydrogen in an alkane is replaced with something else (a functional group, like -OH in the compounds above), the name is derived from the name of the alkane.• The ending denotes the type of compound. Matter – An alcohol ends in -ol. And Measurement © 2009, Prentice-Hall, Inc.
    106. 106. Law of Conservation of Mass “We may lay it down as an incontestable axiom that, in all the operations of art and nature, nothing is created; an equal amount of matter exists both before and after the experiment. Upon this principle, the whole art of performing chemical experiments depends.” --Antoine Lavoisier, 1789 Matter And Measurement © 2009, Prentice-Hall, Inc.
    107. 107. Chemical EquationsChemical equations are conciserepresentations of chemical reactions. Matter And Measurement © 2009, Prentice-Hall, Inc.
    108. 108. Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g) Matter And Measurement © 2009, Prentice-Hall, Inc.
    109. 109. Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g)Reactants appear on the leftside of the equation. Matter And Measurement © 2009, Prentice-Hall, Inc.
    110. 110. Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g)Products appear on theright side of the equation. Matter And Measurement © 2009, Prentice-Hall, Inc.
    111. 111. Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g)The states of the reactants and productsare written in parentheses to the right of Matter Andeach compound. Measurement © 2009, Prentice-Hall, Inc.
    112. 112. Anatomy of a Chemical EquationCH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g) Coefficients are inserted to balance the equation. Matter And Measurement © 2009, Prentice-Hall, Inc.
    113. 113. Subscripts and Coefficients Give Different Information• Subscripts tell the number of atoms of each element in a molecule. Matter And Measurement © 2009, Prentice-Hall, Inc.
    114. 114. Subscripts and Coefficients Give Different Information• Subscripts tell the number of atoms of each element in a molecule• Coefficients tell the number of Matter And molecules. Measurement © 2009, Prentice-Hall, Inc.
    115. 115. Reaction Types Matter And Measurement © 2009, Prentice-Hall, Inc.
    116. 116. Combination Reactions • In this type of reaction two or more substances react to form one product.• Examples: – 2 Mg (s) + O2 (g) → 2 MgO (s) – N2 (g) + 3 H2 (g) → 2 NH3 (g) Matter – C3H6 (g) + Br2 (l) → C3H6Br2 (l) And Measurement © 2009, Prentice-Hall, Inc.
    117. 117. Decomposition Reactions • In a decomposition one substance breaks down into two or more substances.• Examples: – CaCO3 (s) → CaO (s) + CO2 (g) – 2 KClO3 (s) → 2 KCl (s) + O2 (g) Matter – 2 NaN3 (s) → 2 Na (s) + 3 N2 (g) And Measurement © 2009, Prentice-Hall, Inc.
    118. 118. Combustion Reactions • These are generally rapid reactions that produce a flame. • Most often involve hydrocarbons reacting with oxygen in the air.• Examples: – CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g) Matter – C3H8 (g) + 5 O2 (g) → 3 CO2 (g) + 4 H2O (g) And Measurement © 2009, Prentice-Hall, Inc.
    119. 119. FormulaWeights Matter And Measurement © 2009, Prentice-Hall, Inc.
    120. 120. Formula Weight (FW)• A formula weight is the sum of the atomic weights for the atoms in a chemical formula.• So, the formula weight of calcium chloride, CaCl2, would be Ca: 1(40.1 amu) + Cl: 2(35.5 amu) 111.1 amu• Formula weights are generally reported for ionic compounds. Matter And Measurement © 2009, Prentice-Hall, Inc.
    121. 121. Molecular Weight (MW)• A molecular weight is the sum of the atomic weights of the atoms in a molecule.• For the molecule ethane, C2H6, the molecular weight would be C: 2(12.0 amu) + H: 6(1.0 amu) 30.0 amu Matter And Measurement © 2009, Prentice-Hall, Inc.
    122. 122. Percent Composition One can find the percentage of the mass of a compound that comes from each of the elements in the compound by using this equation: (number of atoms)(atomic weight)% element = x 100 (FW of the compound) Matter And Measurement © 2009, Prentice-Hall, Inc.
    123. 123. Percent CompositionSo the percentage of carbon in ethaneis… (2)(12.0 amu) %C = (30.0 amu) 24.0 amu = x 100 30.0 amu = 80.0% Matter And Measurement © 2009, Prentice-Hall, Inc.
    124. 124. Moles Matter And Measurement © 2009, Prentice-Hall, Inc.
    125. 125. Avogadro’s Number• 6.02 x 1023• 1 mole of 12C has a mass of 12 g. Matter And Measurement © 2009, Prentice-Hall, Inc.
    126. 126. Molar Mass• By definition, a molar mass is the mass of 1 mol of a substance (i.e., g/mol). – The molar mass of an element is the mass number for the element that we find on the periodic table. – The formula weight (in amu’s) will be the same number as the molar mass (in g/mol). Matter And Measurement © 2009, Prentice-Hall, Inc.
    127. 127. Using MolesMoles provide a bridge from the molecularscale to the real-world scale. Matter And Measurement © 2009, Prentice-Hall, Inc.
    128. 128. Mole Relationships• One mole of atoms, ions, or molecules contains Avogadro’s number of those particles.• One mole of molecules or formula units contains Avogadro’s number times the number of atoms or ions of each element in the compound. Matter And Measurement © 2009, Prentice-Hall, Inc.
    129. 129. FindingEmpiricalFormulas Matter And Measurement © 2009, Prentice-Hall, Inc.
    130. 130. Calculating Empirical FormulasOne can calculate the empirical formula fromthe percent composition. Matter And Measurement © 2009, Prentice-Hall, Inc.
    131. 131. Calculating Empirical FormulasThe compound para-aminobenzoic acid (you may haveseen it listed as PABA on your bottle of sunscreen) iscomposed of carbon (61.31%), hydrogen (5.14%),nitrogen (10.21%), and oxygen (23.33%). Find theempirical formula of PABA. Matter And Measurement © 2009, Prentice-Hall, Inc.
    132. 132. Calculating Empirical FormulasAssuming 100.00 g of para-aminobenzoic acid, C: 61.31 g x 1 mol = 5.105 mol C 12.01 g 1 mol H: 5.14 g x = 5.09 mol H 1.01 g 1 mol N: 10.21 g x = 0.7288 mol N 14.01 g 1 mol O: 23.33 g x = 1.456 mol O 16.00 g Matter And Measurement © 2009, Prentice-Hall, Inc.
    133. 133. Calculating Empirical FormulasCalculate the mole ratio by dividing by the smallest numberof moles: 5.105 mol C: = 7.005 ≈ 7 0.7288 mol 5.09 mol H: = 6.984 ≈ 7 0.7288 mol 0.7288 mol N: = 1.000 0.7288 mol 1.458 mol O: = 2.001 ≈ 2 Matter 0.7288 mol And Measurement © 2009, Prentice-Hall, Inc.
    134. 134. Calculating Empirical FormulasThese are the subscripts for the empirical formula: C7H7NO2 Matter And Measurement © 2009, Prentice-Hall, Inc.
    135. 135. Combustion Analysis• Compounds containing C, H and O are routinely analyzed through combustion in a chamber like this. – C is determined from the mass of CO2 produced. – H is determined from the mass of H2O produced. – O is determined by difference after the C and H have been determined. Matter And Measurement © 2009, Prentice-Hall, Inc.
    136. 136. Elemental Analyses Compounds containing other elements are analyzed using methods analogous to those used for C, H and O. Matter And Measurement © 2009, Prentice-Hall, Inc.
    137. 137. Stoichiometric CalculationsThe coefficients in the balanced equation givethe ratio of moles of reactants and products. Matter And Measurement © 2009, Prentice-Hall, Inc.
    138. 138. Stoichiometric CalculationsStarting with themass of SubstanceA you can use theratio of thecoefficients of A andB to calculate themass of SubstanceB formed (if it’s aproduct) or used (ifit’s a reactant). Matter And Measurement © 2009, Prentice-Hall, Inc.
    139. 139. Stoichiometric Calculations C6H12O6 + 6 O2 → 6 CO2 + 6 H2OStarting with 1.00 g of C6H12O6…we calculate the moles of C6H12O6…use the coefficients to find the moles of H2O… Matterand then turn the moles of water to grams. And Measurement © 2009, Prentice-Hall, Inc.
    140. 140. LimitingReactants Matter And Measurement © 2009, Prentice-Hall, Inc.
    141. 141. How Many Cookies Can I Make? • You can make cookies until you run out of one of the ingredients. • Once this family runs out of sugar, they will stop making cookies (at least any cookies you would want to eat). Matter And Measurement © 2009, Prentice-Hall, Inc.
    142. 142. How Many Cookies Can I Make? • In this example the sugar would be the limiting reactant, because it will limit the amount of cookies you can make. Matter And Measurement © 2009, Prentice-Hall, Inc.
    143. 143. Limiting Reactants• The limiting reactant is the reactant present in the smallest stoichiometric amount. – In other words, it’s the reactant you’ll run out of first (in this case, the H2). Matter And Measurement © 2009, Prentice-Hall, Inc.
    144. 144. Limiting ReactantsIn the example below, the O2 would be theexcess reagent. Matter And Measurement © 2009, Prentice-Hall, Inc.
    145. 145. Theoretical Yield• The theoretical yield is the maximum amount of product that can be made. – In other words it’s the amount of product possible as calculated through the stoichiometry problem.• This is different from the actual yield, which is the amount one actually produces and measures. Matter And Measurement © 2009, Prentice-Hall, Inc.
    146. 146. Percent Yield One finds the percent yield by comparing the amount actually obtained (actual yield) to the amount it was possible to make (theoretical yield). Actual YieldPercent Yield = x 100 Theoretical Yield Matter And Measurement © 2009, Prentice-Hall, Inc.
    147. 147. Solutions • Solutions are defined as homogeneous mixtures of two or more pure substances. • The solvent is present in greatest abundance. • All other substances are solutes. Matter And Measurement © 2009, Prentice-Hall, Inc.
    148. 148. Dissociation • When an ionic substance dissolves in water, the solvent pulls the individual ions from the crystal and solvates them. • This process is called dissociation. Matter And Measurement © 2009, Prentice-Hall, Inc.
    149. 149. Dissociation • An electrolyte is a substances that dissociates into ions when dissolved in water. Matter And Measurement © 2009, Prentice-Hall, Inc.
    150. 150. Electrolytes • An electrolyte is a substances that dissociates into ions when dissolved in water. • A nonelectrolyte may dissolve in water, but it does not dissociate into ions when it does Matter so. And Measurement © 2009, Prentice-Hall, Inc.
    151. 151. Electrolytes andNonelectrolytes Soluble ionic compounds tend to be electrolytes. Matter And Measurement © 2009, Prentice-Hall, Inc.
    152. 152. Electrolytes andNonelectrolytes Molecular compounds tend to be nonelectrolytes, except for acids and bases. Matter And Measurement © 2009, Prentice-Hall, Inc.
    153. 153. Electrolytes• A strong electrolyte dissociates completely when dissolved in water.• A weak electrolyte only dissociates partially when dissolved in water. Matter And Measurement © 2009, Prentice-Hall, Inc.
    154. 154. Strong Electrolytes Are…• Strong acids• Strong bases Matter And Measurement © 2009, Prentice-Hall, Inc.
    155. 155. Strong Electrolytes Are…• Strong acids• Strong bases• Soluble ionic salts Matter And Measurement © 2009, Prentice-Hall, Inc.
    156. 156. Precipitation ReactionsWhen one mixes ionsthat form compoundsthat are insoluble (ascould be predicted bythe solubilityguidelines), aprecipitate is formed. Matter And Measurement © 2009, Prentice-Hall, Inc.
    157. 157. Metathesis (Exchange) Reactions • Metathesis comes from a Greek word that means “to transpose.” AgNO3 (aq) + KCl (aq) → AgCl (s) + KNO3 (aq) Matter And Measurement © 2009, Prentice-Hall, Inc.
    158. 158. Metathesis (Exchange) Reactions • Metathesis comes from a Greek word that means “to transpose.” • It appears the ions in the reactant compounds exchange, or transpose, ions. AgNO3 (aq) + KCl (aq) → AgCl (s) + KNO3 (aq) Matter And Measurement © 2009, Prentice-Hall, Inc.
    159. 159. Solubility of different compounds (NS = non soluble in water, S = soluble in water) Cl- Br- I- NO3- SO42- CO32- PO43-Li+ S S S S S S S SNa+ S S S S S S S SK+ S S S S S S S SMg2+ NS S S S S S NS NSCa2+ S S S S S S NS NSSr2+ S S S S S NS NS NSBa2+ S S S S S NS NS NSFe2+ NS S S S S S NS NSFe3+ NS S S S S S NS NSNi2+ NS S S S S S NS NSCu+ NS S S S S S NS NSCu2+ NS S S S S S NS NSAl3+ NS S S S S S NS NSZn2+ NS S S S S S NS NSAg+ NS NS NS NS S S NS NSPb2+ NS NS NS NS S NS NS NS Matter And Measurement
    160. 160. Solution Chemistry• It is helpful to pay attention to exactly what species are present in a reaction mixture (i.e., solid, liquid, gas, aqueous solution).• If we are to understand reactivity, we must be aware of just what is changing during the course of a reaction. Matter And Measurement © 2009, Prentice-Hall, Inc.
    161. 161. Molecular EquationThe molecular equation lists the reactantsand products in their molecular form.AgNO3 (aq) + KCl (aq) → AgCl (s) + KNO3 (aq) Matter And Measurement © 2009, Prentice-Hall, Inc.
    162. 162. Ionic Equation• In the ionic equation all strong electrolytes (strong acids, strong bases, and soluble ionic salts) are dissociated into their ions.• This more accurately reflects the species that are found in the reaction mixture. Ag+ (aq) + NO3- (aq) + K+ (aq) + Cl- (aq) → AgCl (s) + K+ (aq) + NO3- (aq) Matter And Measurement © 2009, Prentice-Hall, Inc.
    163. 163. Net Ionic Equation• To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right. Ag+(aq) + NO3-(aq) + K+(aq) + Cl-(aq) → Matter AgCl (s) + K+(aq) + NO3-(aq) And Measurement © 2009, Prentice-Hall, Inc.
    164. 164. Net Ionic Equation• To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right.• The only things left in the equation are those things that change (i.e., react) during the course of the reaction. Ag+(aq) + Cl-(aq) → AgCl (s) Matter And Measurement © 2009, Prentice-Hall, Inc.
    165. 165. Net Ionic Equation• To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right.• The only things left in the equation are those things that change (i.e., react) during the course of the reaction.• Those things that didn’t change (and were deleted from the net ionic equation) are called spectator ions. Ag+(aq) + NO3-(aq) + K+(aq) + Cl-(aq) → Matter AgCl (s) + K+(aq) + NO3-(aq) And Measurement © 2009, Prentice-Hall, Inc.
    166. 166. Writing Net Ionic Equations1. Write a balanced molecular equation.2. Dissociate all strong electrolytes.3. Cross out anything that remains unchanged from the left side to the right side of the equation.4. Write the net ionic equation with the species that remain. Matter And Measurement © 2009, Prentice-Hall, Inc.
    167. 167. Acids • Arrhenius defined acids as substances that increase the concentration of H+ when dissolved in water. • Brønsted and Lowry defined them as proton donors. Matter And Measurement © 2009, Prentice-Hall, Inc.
    168. 168. Acids There are only seven strong acids: • Hydrochloric (HCl) • Hydrobromic (HBr) • Hydroiodic (HI) • Nitric (HNO3) • Sulfuric (H2SO4) • Chloric (HClO3) • Perchloric (HClO4) Matter And Measurement © 2009, Prentice-Hall, Inc.
    169. 169. Bases• Arrhenius defined bases as substances that increase the concentration of OH− when dissolved in water.• Brønsted and Lowry defined them as proton acceptors. Matter And Measurement © 2009, Prentice-Hall, Inc.
    170. 170. BasesThe strong basesare the solublemetal salts ofhydroxide ion:• Alkali metals• Calcium• Strontium• Barium Matter And Measurement © 2009, Prentice-Hall, Inc.
    171. 171. Acid-Base Reactions In an acid-base reaction, the acid donates a proton (H+) to the base. Matter And Measurement © 2009, Prentice-Hall, Inc.
    172. 172. Neutralization Reactions Generally, when solutions of an acid and a base are combined, the products are a salt and water.CH3COOH (aq) + NaOH (aq) →CH3COONa (aq) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    173. 173. Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is… HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    174. 174. Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is… HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) H+ (aq) + Cl- (aq) + Na+ (aq) + OH-(aq) → Na+ (aq) + Cl- (aq) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    175. 175. Neutralization ReactionsWhen a strong acid reacts with a strong base, the netionic equation is… HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) H+ (aq) + Cl- (aq) + Na+ (aq) + OH-(aq) → Na+ (aq) + Cl- (aq) + H2O (l) H+ (aq) + OH- (aq) → H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    176. 176. Gas-Forming Reactions • Some metathesis reactions do not give the product expected. • In this reaction, the expected product (H2CO3) decomposes to give a gaseous product (CO2).CaCO3 (s) + HCl (aq) →CaCl2 (aq) + CO2 (g) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    177. 177. Gas-Forming Reactions When a carbonate or bicarbonate reacts with an acid, the products are a salt, carbon dioxide, and water. CaCO3 (s) + HCl (aq) →CaCl2 (aq) + CO2 (g) + H2O (l)NaHCO3 (aq) + HBr (aq) →NaBr (aq) + CO2 (g) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    178. 178. Gas-Forming Reactions Similarly, when a sulfite reacts with an acid, the products are a salt, sulfur dioxide, and water.SrSO3 (s) + 2 HI (aq) →SrI2 (aq) + SO2 (g) + H2O (l) Matter And Measurement © 2009, Prentice-Hall, Inc.
    179. 179. Gas-Forming Reactions• This reaction gives the predicted product, but you had better carry it out in the hood, or you will be very unpopular!• But just as in the previous examples, a gas is formed as a product of this reaction.Na2S (aq) + H2SO4 (aq) → Na2SO4 (aq) + H2S (g) Matter And Measurement © 2009, Prentice-Hall, Inc.
    180. 180. Oxidation-Reduction Reactions• An oxidation occurs when an atom or ion loses electrons.• A reduction occurs when an atom or ion gains electrons.• One cannot occur without the other. Matter And Measurement © 2009, Prentice-Hall, Inc.
    181. 181. Oxidation NumbersTo determine if an oxidation-reductionreaction has occurred, we assign anoxidation number to each element in aneutral compound or charged entity. Matter And Measurement © 2009, Prentice-Hall, Inc.
    182. 182. Oxidation Numbers• Elements in their elemental form have an oxidation number of 0.• The oxidation number of a monatomic ion is the same as its charge. Matter And Measurement © 2009, Prentice-Hall, Inc.
    183. 183. Oxidation Numbers• Nonmetals tend to have negative oxidation numbers, although some are positive in certain compounds or ions. Oxygen has an oxidation number of −2, except in the peroxide ion in which it has an oxidation number of −1. Hydrogen is −1 when bonded to a metal, +1 when bonded to a nonmetal. Matter And Measurement © 2009, Prentice-Hall, Inc.
    184. 184. Oxidation Numbers• Nonmetals tend to have negative oxidation numbers, although some are positive in certain compounds or ions. Fluorine always has an oxidation number of −1. The other halogens have an oxidation number of −1 when they are negative; they can have positive oxidation numbers, however, most notably in oxyanions. Matter And Measurement © 2009, Prentice-Hall, Inc.
    185. 185. Oxidation Numbers• The sum of the oxidation numbers in a neutral compound is 0.• The sum of the oxidation numbers in a polyatomic ion is the charge on the ion. Matter And Measurement © 2009, Prentice-Hall, Inc.
    186. 186. Displacement Reactions • In displacement reactions, ions oxidize an element. • The ions, then, are reduced. Matter And Measurement © 2009, Prentice-Hall, Inc.
    187. 187. Displacement Reactions In this reaction, silver ions oxidize copper metal.Cu (s) + 2 Ag+ (aq) → Cu2+ (aq) + 2 Ag (s) Matter And Measurement © 2009, Prentice-Hall, Inc.
    188. 188. Displacement Reactions The reverse reaction, however, does not occur. xCu2+ (aq) + 2 Ag (s) → Cu (s) + 2 Ag+ (aq) Matter And Measurement © 2009, Prentice-Hall, Inc.
    189. 189. Activity Series Matter And Measurement © 2009, Prentice-Hall, Inc.
    190. 190. Molarity• Two solutions can contain the same compounds but be quite different because the proportions of those compounds are different.• Molarity is one way to measure the concentration of a solution. moles of solute Molarity (M) = volume of solution in liters Matter And Measurement © 2009, Prentice-Hall, Inc.
    191. 191. Mixing a Solution • To create a solution of a known molarity, one weighs out a known mass (and, therefore, number of moles) of the solute. • The solute is added to a volumetric flask, and solvent is added to the line on the neck of the flask. Matter And Measurement © 2009, Prentice-Hall, Inc.
    192. 192. Dilution• One can also dilute a more concentrated solution by – Using a pipet to deliver a volume of the solution to a new volumetric flask, and – Adding solvent to the line on the neck of the new flask. Matter And Measurement © 2009, Prentice-Hall, Inc.
    193. 193. DilutionThe molarity of the new solution can be determinedfrom the equation Mc × Vc = Md × Vd,where Mc and Md are the molarity of the concentrated and dilutesolutions, respectively, and Vc and Vd are the volumes of thetwo solutions. Matter And Measurement © 2009, Prentice-Hall, Inc.
    194. 194. Using Molarities inStoichiometric Calculations Matter And Measurement © 2009, Prentice-Hall, Inc.
    195. 195. Titration Titration is an analytical technique in which one can calculate the concentration of a solute in a solution. Matter And Measurement © 2009, Prentice-Hall, Inc.
    196. 196. Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 5 Thermochemistry John D. Bookstaver MatterSt. Charles Community College And Cottleville, MO Measurement © 2009, Prentice-Hall, Inc.
    197. 197. Energy• Energy is the ability to do work or transfer heat. – Energy used to cause an object that has mass to move is called work. – Energy used to cause the temperature of an object to rise is called heat. Matter And Measurement © 2009, Prentice-Hall, Inc.
    198. 198. Potential EnergyPotential energy is energy an objectpossesses by virtue of its position or chemicalcomposition. Matter And Measurement © 2009, Prentice-Hall, Inc.
    199. 199. Kinetic EnergyKinetic energy is energy an object possessesby virtue of its motion. 1 KE =  mv2 2 Matter And Measurement © 2009, Prentice-Hall, Inc.
    200. 200. Units of Energy• The SI unit of energy is the joule (J). kg m2 1 J = 1  s2• An older, non-SI unit is still in widespread use: the calorie (cal). 1 cal = 4.184 J Matter And Measurement © 2009, Prentice-Hall, Inc.
    201. 201. Definitions:System and Surroundings • The system includes the molecules we want to study (here, the hydrogen and oxygen molecules). • The surroundings are everything else (here, the cylinder and piston). Matter And Measurement © 2009, Prentice-Hall, Inc.
    202. 202. Definitions: Work• Energy used to move an object over some distance is work.• w=F×d where w is work, F is the force, and d is the distance over which the force is exerted. Matter And Measurement © 2009, Prentice-Hall, Inc.
    203. 203. Heat • Energy can also be transferred as heat. • Heat flows from warmer objects to cooler objects. Matter And Measurement © 2009, Prentice-Hall, Inc.
    204. 204. Conversion of Energy• Energy can be converted from one type to another.• For example, the cyclist above has potential energy as she sits on top of the hill. Matter And Measurement © 2009, Prentice-Hall, Inc.
    205. 205. Conversion of Energy• As she coasts down the hill, her potential energy is converted to kinetic energy.• At the bottom, all the potential energy she had at the top of the hill is now kinetic energy. Matter And Measurement © 2009, Prentice-Hall, Inc.
    206. 206. First Law of Thermodynamics• Energy is neither created nor destroyed.• In other words, the total energy of the universe is a constant; if the system loses energy, it must be gained by the surroundings, and vice versa. Matter And Measurement © 2009, Prentice-Hall, Inc.
    207. 207. Internal EnergyThe internal energy of a system is the sum of allkinetic and potential energies of all componentsof the system; we call it E. Matter And Measurement © 2009, Prentice-Hall, Inc.
    208. 208. Internal EnergyBy definition, the change in internal energy, ∆E,is the final energy of the system minus the initialenergy of the system: ∆E = Efinal − Einitial Matter And Measurement © 2009, Prentice-Hall, Inc.
    209. 209. Changes in Internal Energy • If ∆E > 0, Efinal > Einitial – Therefore, the system absorbed energy from the surroundings. – This energy change is called endergonic. Matter And Measurement © 2009, Prentice-Hall, Inc.
    210. 210. Changes in Internal Energy • If ∆E < 0, Efinal < Einitial – Therefore, the system released energy to the surroundings. – This energy change is called exergonic. Matter And Measurement © 2009, Prentice-Hall, Inc.
    211. 211. Changes in Internal Energy • When energy is exchanged between the system and the surroundings, it is exchanged as either heat (q) or work (w). • That is, ∆E = q + w. Matter And Measurement © 2009, Prentice-Hall, Inc.
    212. 212. ∆E, q, w, and Their Signs Matter And Measurement © 2009, Prentice-Hall, Inc.
    213. 213. Exchange of Heat between System and Surroundings• When heat is absorbed by the system from the surroundings, the process is endothermic. Matter And Measurement © 2009, Prentice-Hall, Inc.
    214. 214. Exchange of Heat between System and Surroundings• When heat is absorbed by the system from the surroundings, the process is endothermic.• When heat is released by the system into the surroundings, the process is exothermic. Matter And Measurement © 2009, Prentice-Hall, Inc.
    215. 215. State FunctionsUsually we have no way of knowing theinternal energy of a system; finding that valueis simply too complex a problem. Matter And Measurement © 2009, Prentice-Hall, Inc.
    216. 216. State Functions• However, we do know that the internal energy of a system is independent of the path by which the system achieved that state. – In the system below, the water could have reached room temperature from either direction. Matter And Measurement © 2009, Prentice-Hall, Inc.
    217. 217. State Functions• Therefore, internal energy is a state function.• It depends only on the present state of the system, not on the path by which the system arrived at that state.• And so, ∆E depends only on Einitial and Efinal. Matter And Measurement © 2009, Prentice-Hall, Inc.
    218. 218. State Functions • However, q and w are not state functions. • Whether the battery is shorted out or is discharged by running the fan, its ∆E is the same. – But q and w are different in the two cases. Matter And Measurement © 2009, Prentice-Hall, Inc.
    219. 219. Work Usually in an open container the only work done is by a gas pushing on the surroundings (or by the surroundings pushing on the gas). Matter And Measurement © 2009, Prentice-Hall, Inc.
    220. 220. WorkWe can measure the work done by the gas ifthe reaction is done in a vessel that has beenfitted with a piston. w = -P∆V Matter And Measurement © 2009, Prentice-Hall, Inc.
    221. 221. Enthalpy• If a process takes place at constant pressure (as the majority of processes we study do) and the only work done is this pressure-volume work, we can account for heat flow during the process by measuring the enthalpy of the system.• Enthalpy is the internal energy plus the product of pressure and volume: H = E + PV Matter And Measurement © 2009, Prentice-Hall, Inc.
    222. 222. Enthalpy• When the system changes at constant pressure, the change in enthalpy, ∆H, is ∆H = ∆(E + PV)• This can be written ∆H = ∆E + P∆V Matter And Measurement © 2009, Prentice-Hall, Inc.
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