1. Breaking ThroughChemistryBy: John Mark B. Sebolino

2. Chapter 1. The Nature of ChemistryKey Concepts Chemistry - is the study of matter and thechanges it undergoes. It is sometimes called thecentral science because it overlaps with manyother sciences. Technology - is the application of science. It hasimproved the quality of human life. SI units - are used to express physical quantitiesin all sciences. Metric prefixes are used to makeunits smaller or larger. 3. Precision - is how close several measurementsare to the same value. Accuracy - tells how close a measurement is tothe true or accepted digit. Significant - figures include both the certaindigits and the estimated digit. Scientific notation - is used to write very smallor very large numbers. 4. Dimensional analysis - is the technique that uses conversion factors. The guide to ensure that conversion factor are properly formulated is the cancellation of units. 5. Chapter 2. Matter: Its Composition andOrganization. Key Concepts Matter - is anything that has mass and volume.Properties of matter differ for solids, liquids, andgases. A pure substance is either an element or acompound. An element is a substance thatcannot be broken down to simpler substances. Acompound is formed when two or more elementscombine in a chemical change. 6. A change in the properties of substance without achange in composition is a physical change. Ifthere is a change in the composition of asubstance, a chemical change has occurred.Chemical changes produce matter with newproperties. The physical combination of two or moresubstances is a mixture. A mixture has a variablecomposition. It may be heterogeneous orhomogeneous. Heterogeneous mixtures (coarsemixtures, suspensions, and colloids) do not haveuniform properties throughout, whilehomogeneous mixtures (solutions) have uniform 7. Solutions may be gases, liquids, or solids. The components of a mixture can be separate byphysical methods. Colloids - are mixtures of two or moresolids, liquids, or gases whose particles arebigger than the particles of a solution but smallerthan those of a suspension. Tyndall effect, Brownianmovement, adsorption, and electrical charge arethe properties of colloids. 8. Colloids are prepared and purified bycondensation and dispersion methods. Condensation - is the process of combiningmolecules to form colloidal particles. Dispersion - is the process of breaking downlarge particles to colloidal size. Energy - is the capacity to do work or to transferheat. It is involved whenever matter undergoes achange. 9. Chapter 3. Atomic Theory.Key Concepts Over 2400 years ago, the concept of the atomwas proposed by Greek philosophers. In the early 19th century, Daltons proposed theatomic theory. This theory is related to the threefundamental laws of matter. (1) The total mass of the reactants and productsare constant during a chemical reaction (law ofconservation of mass). 10. (2) Any sample of compound, has elements inthe same proportion (law of definitecomposition). (3) In different compounds of the sameelements, the mass of one element that combineswith a fixed mass of the other can be expressedas a ratio of small whole numbers (law ofmultiple proportions). 11. Thomsons experiment on the behavior ofcathode rays in magnetic and electric field led tothe discovery of the electron and themeasurement of its charge to mass ratio. Millikans oil drop experiment measured thecharge of the electron. Becquerel and the Curies discoveredradioactivity. Rutherfords studies on alpha rays led to thediscovery of nucleus. 12. Atoms have a nucleus that contains protons andneutrons. Electrons move in the space around thenucleus. Elements can be classified by atomic number orthe number of protons in the nucleus of an atom. All atoms of a given element have the sameatomic number. The mass number of an atom isthe number of protons and neutrons. All atoms of the same element that differ in massnumber are known as isotopes. 13. Chapter 4. Electronic Configuration. KeyConcepts The properties of visible light and other forms ofelectromagnetic radiation led to the electronicstructure of atoms. Max Planck proposed that energy is absorbedand emitted in discrete amounts or individualpackets called quanta (plural for quantum). Albert Einstein used Plancks theory to explainthe photoelectric effect. He proposed that lightconsists of quanta of energy which behave liketiny particles of light. He called these energyquanta photons. 14. The concept of quantized electrons grew from thestudy of line spectra of atoms. A line spectrumconsists of quanta of energy which can be usedlike fingerprints to identify the element. Niels Bohr used the line spectra to explainspecific energy levels within the atom. Heproposed the planetary model of the atom. Louis de Broglie discovered the wave nature ofmatter which initiated the development of a newmathematical description of electronconfiguration. 15. Heisenbergs uncertainty principle explained theimpossibility of simultaneously measuring themomentum and location of an electron. Erwin Schrodinger devised the quantummechanical model of the atom which describedelectrons as waves that exist in quantized energylevels. The regions in space around the nucleus whereelectrons are most likely to be found are calledorbitals. These orbitals have various shapes andare labeled s, p, d, and f. Each principal energylevel or shell consists of these orbitals. 16. The manner in which electrons are arrangedaround the nucleus of an atom is called electronconfiguration. The Aufbau principle, the Puali exclusionprinciple, and the Hunds rule are applied inwriting electron configurations. The Aufbau principle tells the sequence in whichorbitals are filled. The Pauli exclusion principle states that amaximum if only two electrons can occupy anorbital. Hunds rule explains that electrons pair up only 17. Chapter 5. The Periodic Table.Key Concepts Different periodic table were developed byDobereiner, Newlands, Mendeleev, and Meyer.The periodic table was based on similarities inproperties and reactivities of elements in theincreasing order of their atomic mass. Discrepancies in these periodic tables wereresolved when Moseley established that eachelement has a unique atomic number andshowed that elements should be arrangedaccording to their increasing atomic number. 18. The periodic table is organized into 18 groups orfamilies and 7 periods or rows. The groups areorganized further into s, p, d, and f blocks basedon how valence electrons fill each sublevel.Elements in a group have similar propertiesbecause they have the same valence electrons. Atomic radius decreases from left to right acrossa period because the positive charge of theatoms increases, which attracts electrons morestrongly. 19. Atomic radius increases down a group becausethe electrons of the atoms fill more energy levels. Ionization energy - is the energy absorbed toremove an electron to form a positive ion. Electron affinity - is the energy when an atomgains an electron forming a negative ion. Electronegativity is the attraction of an atom forelectrons in a chemical bond. 20. The trends for ionization energy, electron affinity,and electronegativity ate the same. They increasefrom left to right of the periodic table anddecrease down a period. Metals are found on the left side of the periodictable. Nonmetals are found on the upper rightside of the periodic table. Metalloids have someproperties of metals and nonmetals. 21. Chapter 6. Chemical Bonds.Key Concepts Chemical bonds are classified into three groups: ionsof opposite charges; covalent bonds, which resultfrom the sharing of electrons by two atoms; andmetallic bond, which are the attractions amongpositively charged ions for delocalized electrons. These bonds involve the valence electrons with thetendency of atoms follow the octet rule. This can berepresented by electron dot symbols or Lewissymbols. Resonance structures are used when a simple Lewisstructure is not adequate to represent a particularmolecule or ion (specie). Some covalent moleculesformed from atoms of the representation groups1, 2, and 3 lack octet configurations while atoms from5, 6, and 7 form expanded octet configurations. 22. A polar covalent bond is formed when electronsare not shared equally between two atoms. Electronegativity difference of bonded atomsdetermines the kind of bond formed between theatoms. The sharing of one pair of electrons produces asingle bond, the sharing of two pairs, a doublebond, and three pairs, a triple bond. Double andtriple bonds are also called multiple bonds. 23. Chapter 7. Molecular Geometry.Key Concepts The shapes of small molecules can de explainedin terms of the VSEPR model which states thatelectron pairs arrange themselves as far apart aspossible to minimize electrostatic repulsion. The geometry of molecules is determined by thearrangement of bonding pairs and lone pairs. The five common shapes of small molecules arelinear, trigonal planar, tetrahedral, trigonalbipyramid, and ictahedral. 24. The electron pair cloud repulsion model suggests thatthe denser the electron clouds, the greater therepulsive force. The order from greatest to leastrepulsive force is that triple bond > double bond >lone pair > single bond (>>1.p.>). Molecules that contain polar bonds (bond dipoles)may be polar or nonpolar molecules, depending onthe shape of the molecules. The properties of polarmolecules (dipole) are different from those ofnonpolar molecules. Valence bond theory - is an extension of the Lewiscovalent bond. In this theory, bonds are formed whenneighboring atoms overlap and the potential energy ofthe system decreases. The greater the overlap, thestronger the bond formed. 25. Shapes of molecules are also described in termsof hybrid orbitals. The process of hybridizationinvolves the promotion of electron to emptyorbital(s) and mixing of the orbitals to formequivalent numbers of hybrid orbitals. Hybridorbitals can overlap with orbitals of other atoms tomake bonds. Or they can accommodate lonepairs. Covalent bonds that overlap end to end along theline connecting the atoms are called sigma ()bonds. When p orbitals overlap on a side to sideorientation perpendicular to the line connectingthe atoms, these are called pi () bonds. 26. Chapter 8. Chemical Names andFormulas.Key Concepts The charges or oxidation numbers of the ions ofrepresentative elements are determined by theirposition in the periodic table. Most transition metals have more that one commonionic or oxidation numbers. A polyatomic ion is agroup of atoms that behaves as an ion ide. Ifcations have more than one ionic charge, a Romannumeral is used in the name. Ternary ionic compounds contain at least onepolyatomic ion. The names of these compounds endin ite or ate. Binary molecular compounds are composed of twononmetallic elements. Prefixes are used to indicatethe number of atoms each element that are present in 27. Binary acid are compounds that contain hydrogenand nonmetal ions. They are named by using theprefix hydro followed by the name of the anionending in ic acid. Ternary acid contain hydrogen and polyatomicions. They are named by using the name of thepolyatomic ion ending in ic or - ous acid Based are compounds containing a metal ion andhydroxide ion(OH). Bases are named by writingthe name of the cation followed by hydroxide. Salts are named by using the name of the cationfollowed by the name of the anion. 28. Chapter 9. Chemical Reactions.Key Concept Chemical reactions are represented by chemicalequations. The substances that undergo chemical changesare the reactants and the substances formed arethe products. Chemical equations must be balanced to beconsistent with the law of conservation of mass.In balancing an equation, appropriate coefficientsare placed before the formulas of the reactantsand products so that the same number of atomsof each element appears on each side of theequation. 29. The state of a substance in an equation isdetonated by (s), (1), and (g) for solid, liquid, andgas, respectively. A substance dissolved in wateris denoted by (aq) for aqueous. If heat, light, orelectricity is used to initiate the reaction, itsprocess or symbol is written above the arrow. If acatalyst is used to increase the speed ofreaction, its formula or symbol is also writtenabove the arrow. In a combination reaction, two or moreelements or compounds combine to produce asingle product. 30. In a decomposition reaction, a singlecompound is broken into two or more simplersubstances. In a single replacement reaction, a morechemically active element displaces a substancebelow it in the activity series. A double replacement reaction involves theexchange of cations and anions between twocompounds. Replacement reactions can bewritten as net ionic equations. In a combustion reaction, oxygen is always oneof the reactants. 31. Chapter 10. Stoichiometry.Key Concept A mole is the amount of substance that contains6.02 1023 particles or species. The representative particles of elements are theatoms. Molecules are representative particles ofmolecular compounds and diatomic elements. The representative particles for ionic compoundsare formula units. The mass of a mole ofatoms, molecules, or ions is its formula weightexpressed in grams called molar mass. A mole is defined in terms of the number ofparticles in a substance or the mass in grams ofthe substance. The mole can be used inconverting among different units. 32. Percent composition of a compound is thepercent by mass of each element in a compound. Empirical formula is the simplest whole-numberratio of atoms of elements in a compound. Thiscan be calculated from the percent composition ofa compound. Molecular formula shows the actual number ofatoms of each element in a compound. It may bethe same as or a multiple of an empirical formula. Stoichiometry is the study of the quantitativerelationship of individual compounds in chemicalreactions. 33. The coefficients in a balanced equation representthe relative number of moles of each substance.Coefficients are used in establishing conversionfactors as mole ratios in solving stoichiometricproblems. The conversion factor relates the mole of a givensubstance to the moles of the requiredsubstance. Units such as grams and particles areconverted to moles when solving stoichiometricproblems. When reactants supplied are not in the exactamounts required by the balanced equation, thatwhich is used up is the limiting reagent and thatwhich remains after the reaction is completed is 34. The theoretical yield is the amount of productobtained when all of the limiting reagent is usedup. The actual yield is the product formed when theactual reaction is carried out. The percent yield is the ratio of the actual yieldto the theoretical yield expressed in percent. 35. Chapter 11. GasesKey Concept The physical properties of gases are given by fourquantities: Pressure P Volume V Temperature T Amount of Gases n The behavior of gases can be explained by the kineticmolecular theory. The standard temperature and pressure (STP) is 0Cand 1 atm. Atmospheric pressure is the pressure exerted by thegases (air) around us which is 1 atm or 760 mm HG. 36. Boyles law states that the pressure and volume of a gasare inversely proportional to its absolute temperature(constant n and T). Charles law states that the volume of a gas is directlyproportional to its absolute temperature (constant n and P). Avogadros law states that equal volumes of gases containthe same number of particles (constant T and P). Ideal gas equation PV=nRT is a combination of the gaslaws. Daltons law states that the pressure of a mixture of gasesis the sum of the partial pressure of the component gases. Real gases behave like ideal gases in ordinary conditionsexcept at high pressure and low temperature. Lighter gases diffuse and effuse faster than heavier gasesdo. 37. Chapter 12. Liquids and SolidsKey Concept At room temperature, substances with weakintermolecular forces of attraction are gases;those with moderate intermolecular forces areliquids; and those with strong intermolecularforces are solids. Intermolecular forces include ion-dipoleforces, dipole-dipole forces, London dispersionforces and hydrogen bonds. Physicals properties of liquids and solids areexplained by the kinetic molecular theory. 38. Liquids possess properties such asviscosity, surface tension, capillarityevaporation, boiling point, and criticaltemperature and pressure. Heating curve is a plot of temperature versusheat for phase changes. The properties of solids are explained based ontheir nature and strength if intermolecular forcesof attraction. A phase diagram indicates the states or phasesof a substance under specific temperatures andpressures. 39. Chapter 13. SolutionsKey Concept Solutions are homogeneous mixtures of two or moresubstances in a single phase. A solutions is made of solute, the substance thatdissolves, and solvent, the substance in which thesolute is dissolved. A substance that dissolves inanother substance is soluble (miscible) and if it doesnot, it is insoluble (immiscible). Solutions are either gaseous, liquids, or solidsolutions. In preparing dilute solutions form concentratedsolutions, the number of moles before dilutions isequal to the number of moles after dilutions. 40. Saturated solutions contains the maximumamount of solute it can dissolve at a giventemperature. Unsaturated a solutions that contains less thanthe maximum. Supersaturated a solution with more than themaximum. Solubility is the extent to which a solute dissolvesin a given solvent. 41. Chapter 14. Chemical KineticsKey Concept Chemical kinetics is the study of rate andsequence of steps by which chemical reactionsoccur. The rate of a reaction is the measure of howreactants turn into products. Collisions theory assumes that particles collide atthe proper orientation and with sufficient energy inorder to react. Activation energy is the minimum energy requiredfor a chemical reaction to occur and make thereactant form an activated complex or transitionstate. 42. The factors that affect the rate at which a chemicalreaction proceed are nature of thereactants, concentration of the reactants, temperatureat which reaction occurs. A rate law for a reaction describes the relationshipbetween the concentration of reactants and thereaction rate. Most chemical reactions proceed through a series ofelementary steps. The series of steps called thereaction mechanism. The slow reaction in a reaction mechanism called therate-determining step. 43. Chapter 15. Thermo chemistryKey Concept Thermodynamics is the study of processes whichinvolve heat transfer and the performance of work. Thermochemistry is the study of this heat exchangeand work on chemical reactions. Energy + Energy = constant: law of conversation ofenergy. 3 types of system : Open Closed Isolated An open system allows the transfer of both energy and matter into and out the system through a boundary or wall. 44. A closed system is only capable of transferringenergy through boundary. An isolated system is not capable of transferringboth energy and matter into and out of the systemthrough a boundary or wall. Heat is a transfer of energy between system andsurrounding due to temperature difference. 45. Chapter 16. Chemical EquilibriumKey Concept Equilibrium is a state at which there is balance offorces. 3 types of equilibrium: Mechanical Thermal Chemical Chemical equilibrium is achieved when the rate of theforward reaction is equal to the rate of the reversereaction and the amount of components remainsunchanged. 46. Reversible reactions is an incomplete reactions.The reaction is represented by using a doubleheaded arrow (). Law of mass reaction states that thecompositions of a reaction mixture can varyaccording to the quantities of components thatare present. 47. Chapter 17. Acids and BasesKey Concept The operational definitions of acids and bases arebased on experimental results from the laboratorywhich includes color change using dyes. Arrhenius acids is a neutral substance thationizes when it dissolves in water to give the H+or hydrogen. Arrhenius base is a neutral substance that givesthe OH-, or hydroxide ion when dissolves inwater. 48. Lewis defines an acids as species that canaccept a pair of electrons while a base is aspecies that can donate a pair of electrons. The degree of ionization, not the concentration,classifies an acid or a base as weak or strong. Compounds with more than one proton to giveare called polyprotic acids. 49. Chapter 18. ElectrochemistryKey Concept Electrochemistry is the branch of chemistry that deals with electricity and its relation to chemical reactions. A chemical reactions were loss of electron(s) is involved id called oxidation while reaction where electron(s) is gained is called reduction. Redox reaction can be balanced by using the oxidation number method or the ion electron method. 50. Electrochemical cell, voltaic cell, or galvanic cell convertschemical energy from spontaneous reaction to produceelectricity. Electrochemical cell is composed of the electrodes andcharge carriers. Anode is the electrode where oxidation occurs. Cathode is where reduction occurs or where electrons areaccepted. There 3 types of electrodes: Inert Metallic Membrane 51. Chapter 19. Nuclear ChemistryKey Concept Many elements have at least one radioactivity isotope orradioisotope. Elements with atomic numbers 83 or greaterare all radioactivity. Radioactivity decay of naturally occurring radioisotopeproduces alpha particles, beta particles, and gammaradiations. The half-life of a radioisotope is the time it takes for one-half of a sample of the isotope decay. In artificial radioactivity or artificial transmutation, thenucleus of an atom is bombarded with a particle orradiation and changed into different nuclei. 52. In balancing nuclear equation, the sum of themass numbers and atomic numbers of reactantsmust be equal to the sum of the mass numbersand atomic numbers of the product. The mass defect in a nucleus is due to the strongforces of attraction that bind nucleons together. 53. Chapter 20. Organic ChemistryKey Concept Organic compounds are basically made up of carbonatoms bonded mostly tohydrogen, oxygen, nitrogen, and sulfur. Organic chemistry the study of the carbon-basedcompounds. Hydrocarbons are made up of carbons andhydrogens. Alkanes also called saturated hydrocarbons, have ansp3 hybridization, four sigma bonds with no pi bondsthat can be bound to H or C atoms. 54. Alkenes are hydrocarbon containing a carbon-carbondouble bond. Alkynes are hydrocarbons containing a carbon-carbontriple bond. Cycloalkanes are aliphatic cyclic (alicyclic)compounds which have general ring structurecontaining CH-. A molecule can only be aromatic if it has the followingproperties: (1) the molecule is planar and (2) has a monocyclic system of conjugation with a totalof (4n + 2) p electrons where n is an integer.