Solubility Rules: -NO3-1 all soluble -OH- all insoluble except Group 1, Ba(OH)2, Sr(OH)2, Ca(OH)2 -Cl- all soluble except AgCl, Hg2Cl2 and PbCl2 -CO3-2 all insoluble except NH4+ and Group 1 -SO4-2 all soluble except BaSO4, PbSO4 and SrSO4 -S-2 all insoluble except Group 1 and Group 2 and NH4+ Polyatomics: Acids: -Acetate (C2H3O2-1) -Carbonate (CO3-2) -Arsenate (AsO4-3) -HCl = hydrochloric -Chlorate (ClO3-1) -Chromate (CrO4-2) -Arsenite (AsO3-3) -H2SO4 = sulfuric -Chlorite (ClO2-1) -Dichromate (Cr2O7-2) -Phosphate (PO4-3) -HNO3 = nitric -Cyanide (CN-1) -Oxalate (C2O4-2) -Phosphite (PO3-3) -CH3COOH = acetic -Hydroxide (OH-1) -Sulfate (SO4-2) -Ammonium (NH4+1) -H3PO4 = phosphoric -Nitrate (NO3-1) -Sulfite (SO3-2) -Bicarbonate (HCO3-1) -H2CO3 = carbonic -Nitrite (NO2-1) -Nitrite (NO2-1) Matter is the physical material of the universe and exists in 3 states: solid, liquid, gas Substance is matter that has a uniform and definite composition Mixture is a physical blend of substances Homogenous Mixture has uniform composition throughout (solution) Heterogeneous Mixture does not Physical Properties: observed or measured Chemical Properties: ability to undergo chemical change Law of Conservation of Mass: matter/mass can be neither created nor destroyed Extensive Properties: mass and volume Intensive Properties: composition Solid: definite shape, volume, not easily compressed Liquid: indefinite shape, definite volume, not easily compressed Gas: indefinite shape, volume, easily compressed *Particles are always moving in S, L, G Indications of Chemical Reaction: dissolving, releasing/absorption of heat, production of gas, color change, precipitate Qualitative give descriptions, no numbers Quantitative number-based Accuracy is how close to a single measurement Precision is how close several measurements are together Error = |expt – accepted| % Error = |expt-accepted|/accepted * 100 Percent Yield = expt/theoretical * 100 micro=106 1 kilo(unit) = 1000 (unit) 1 (unit) = 1000 milli 1 (unit) = 100 centi K = C + 273 BP=373KDensity = mass/volume C = K – 273 H2O FP=273K Sig Figs: For addition & subtraction use least # of decimal places nano=109 Density of H2O = 1 g/mL / For Multiplication & Division use least # of sig figs Dalton’s Atomic Theory: 1) all elements are composed of atoms 2) atoms of same element are identical 3) atoms can physically mix/chemically combine 4) chemical rxns happen; atoms don’t change Proton = pos., change = radioactivity in whole #d ratios Neutron = neutral, change = isotope Electron = neg., change = ion AMU = atomic mass unit = 1/12th Carbon 12 atom (average atomic mass) Electrons found in electron cloud, move around in orbital, movement creates electricity Quantum Mechanical Model: atom has no definite shape, increase in # of electrons = increase in size & energy Sublevels = s (max 2e-), p (max 6e-), d (max 10e-), f (max 14e-) Energy Levels (n) = 1,2,3,4,5,6,7 (rows on PT) Aufbau Principle: electrons enter @ lowest E level Pauli Exclusion: atomic orbital may have at most 2 electrons Hund’s Rule: when electrons occupy orbitals, one electron enters each orbital until all orbitals contain one electron **Exceptions based on Aufbau principle; due to stable electron-electron interactions; now unstable __________________________________________________________________________________________________ Frequency = Speed of Light/Wave Length Speed of Light = 3.0 x 108 m/s or 3.0 x 1010 cm/s Atomic Spectra Principles: 1) Light is a form of energy called Electromagnetic Radiation 2) Waves have wavelength and frequency 3) Electromagnetic Radiation includes broad spectrum of radiant E 4) Speed of wave = wavelength x frequency 5) Energy is directly proportional to frequency; freq. & w.l. are inversely *When you excite electrons you increase energy which is given off as heat and light = atomic spectra Dmitri Mendeleev arranged elements by ATOMIC MASS Periods are rows / energy levels (1-7) Henry Moseley arranged by ATOMIC NUMBER Groups are vertical columns (18); A = representative elements, B = transitions Periodic Law states when elements are arranged in order of incr. atomic #, there is a periodic pattern in properties Noble Gases – inert gases (stable) VIIIA Halogens – salt formers VIIA Alkali Metals – most reactive IA Transitions – group B Lanthanides (inner transition) 4f Alkaline Earth Metals – IIA & Actinides (inner transition) 5f Atomic & Ionic Radii – distance bet. 1 nuclear to another Ionic Size – size of a charged atom Ionization Energy – amt of energy to remove 1 electron Electronegativity – amt of energy to attract 1 electron *Flourine (F) has highest Ionization E & Electronegativity *Francium (Fr) has greatest atomic/ionic radii & size Cations give up electrons (metals) Anions take electrons (nonmetals) Molecular Compounds: composed of molecules, only nonmetals, named using prefixes Ionic Compounds: composed of ions, have metal as cation, name without prefixes Monary Cmpd. – 1 element Binary Cmpd. – 2 elements Ternary Cmpd. – 3 elements Diatomics: H2, O2, F2, Br2, Cl2, I2, N2 Prefixes: Mono, Di, Tri, Tetra, Penta, Hexa, Hepta, Octa, Nona, Deca Endings: -ide = periodic table -ite/ate: polyatomic Ionic bonding – transfer of electrons, makes ionic compounds; cations must be metal Ions bond to complete their Octet Rule (have full outer electron shell) Seen through Lewis Dot Diagram Metallic bonding – a more specific type of ionic bonding Salts – metal cation + halogen; most are solid at STP, in 3D pattern, conduct electricity as liquid, ductile & malleable Law of Definite Properties – masses of elements are in SAME PROPORTIONS within same compound Law of Multiple Proportions – can compare masses of same element between similar compounds via small #d ratios Covalent bonding – the sharing of electrons; 1 pair = 2 e-, 2 pair = 4 e-, 3 pair = 6 eNonbonding Sites: IA (1; 1 valence e), IVA (4; 4 valence e), VA (3; 5 valence e), VIA (2; 6 valence e), VIIA (1; 7 valence e) Coordinate Covalent –sharing of unshared pairs (NH3 -> NH4+1) Resonance – 2+ orientations of same compound (CO 3-2) Paramagnetism – strong attraction forces to ext. magnetic field (NO2) Dimagnetism – “balanced sharing” (F2) VSEPR Theory – valence shell electron pair repulsion theory; e- repel each other so bond angles adjust Trigonal Planar =120 deg. Tetrahedral =109.5 deg. Trigonal Bipyramidal =90 & 120 deg. Linear =180 deg. Bent =120 deg. Bond Polarity – polar = unequal pulling, nonpolar = equal pulling Bond Dissociation Energy – energy to break bond (kJ) Intermolecular Attractions – Ionic > Hydrogen > Dipole > Dispersion Van der Waals – weakest attractions Dispersion Forces – weakest, caused by e- motion Dipole Interactions – polar molecules attracted to e/o Hydrogen Bonds – H covalently bonded to very EN atom and bonded weakly to unshared e- pair of an EN atom Avogadro’s Number = 6.02 x 1023 representative particles THE MOLE ROAD: Moles Grams = x Molar Mass Moles Rep. Particles = x Av. # Moles Volume @ STP = x 22.4 Grams Moles = / Molar Mass Rep. Particles Moles = / Av. # Volume @ STP Moles = / 22.4 Percent Composition: 1. Determine MM of each compound 2. Determine % of each element in compound Percentage Formula: 1. Assume % = grams 2. Convert grams to moles of each element 3. Divide all mole values by smallest mole value to get “multiplier” for each element Empirical Molecular: 1. Find Empirical Formula MM 2. MF mm/EF mm = multiplier **Know how to balance equations Types of Reactions: 4 base and 2 special = 6 total Reactants Products 1. Synthesis – combination rxn [A+BAB] 2. Decomposition – breakdown rxn [ABA+B] 3. Single Replacement – [A+BYAY+B] 4. Double Replacement – [AX+BYAY+BX] 5. Acid-Base – similar to DR [ACID+BASEH2O+SALT] 6. Combustion – 2 types; only thing that changes is hydrocarbon COMPLETE: Hydrocarbon + O2 CO2 + H2O INCOMPLETE: Hydrocarbon + O2 CO + H2O Solubility Constants and Rules 1-H2O is always a liquid 2-Gases are anything that says “gas”, diatomics, noble gases 3-Solids are all metals except Hg 4-Acids & Bases are always aqueous Net Ionic Equations – 1. Break apart aq compounds 2. Eliminate spectator ions 3. Rewrite and balance Stoichiometric Calculation Steps 1. Change GIVEN/HAVE into moles (reactants) 2. Convert HAVE of first reactant into NEED of second reactant via mole to mole ratio from balanced equation HAVE > NEED = excess b. HAVE < NEED = limiting reagent 3. Take the moles of LR and convert to moles of the specified product then change moles of product into grams This is the THEORETICAL YIELD 4. Determine Percent Yield (Actual Yield/Theoretical Yield) * 100 -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Molarity – tells concentration of ions in an aqueous solution M = moles/liters Kinetic Energy – tiny particles are in constant motion; particle movement affected by volume, pressure, temperature Evaporation = LG Vaporization = LG Condensation = GL Sublimation = go directly from solid to gas [ex: dry ice = solid CO2] Glass = amorphous solid (super cooled liquid) Plasma = gaseous mix of e- and positive ions; very HIGH temp. [ex: Aurora Borealis – the Northern Lights] To speed up kinetic energy = get faster movement = heat it up To slow down = become stationary = solidification Measures entropy (measure of randomness) For gases, collisions are elastic Pressure: atm, kPa, mmHg, Tprr [1 atm = 101.3 kPa = 760 mmHg] result of collisions, no collisions in a vacuum Temperature: Celsius, Fahrenheit, Kelvin; incr. temp = incr KE Volume: mL or L Overall Relationship: only 2 change at a time; P&V are inversely proportional; T changes in same direction but ½ rate Avogadro’s Hypothesis: equal volumes of gases @ same T&P contain equal # of particles [1 mole = 22.4L @ STP] Real vs. Ideal Gases: ideal is hypothetical Boyle’s Law: P1V1=P2V2 [constant = T] Charles’ Law: V1/T1 = V2/T2 [constant =P] OR P1/T1 = P2/T2 [constant = V] Combined Gas Law: P1V1/T1 = P2V2/T2 Dalton’s Partial Pressure: Ptotal = P1 + P2 + P3 etc… Ideal Gas Law: PV = nRT P = pressure [atm (R=0.0821) or kPa (R=8.31)] V= volume n = moles T = Kelvin **Know Exothermic and Endothermic Reaction Graphs Energy transferred through the form of HEAT – determined by changes in temp Exothermic = ∆H is negative, heat LEAVES the system Endothermic = ∆H is positive, heat ENTERS the system Calorimeter – device that contains the heat within a unit, includes a lid and insulated holding device (Styrofoam cup) Q = C x M x ∆T q = heat in joules OR kilojoules M = mass in grams ∆T = change in temp [final-initial] C = specific heat constant – 4.18 joules for water, 1 calorie for water ∆Hfus = molar heat of fusion ∆Hcond = molar heat of condensation ∆Hsolid = molar heat of solidification ∆Hsoln = molar heat of solution **Know heat to mole ratio **Know Hess’s Law of Summation Arrhenius (looks): Acid = H+ or H3O+; Base = OH- ∆Hvap = molar heat of vaporization Bronsted-Lowry (behaves): Acid = Donates H+; Base = Accepts H+ Acids - # of Hs indicate strength of acid; more Hs means it can ionize more than once HCl = monoprotic ionize once H2SO4 = diprotic ionize twice H3PO4 = triprotic ionize thrice Bases - # of OHs tell solubility of base in water; more OHs means less soluble pH = -log [H+] pOH = -log [OH-] pH + pOH = 14 Neutralization Reactions – Acid + Base H2O + Salt Saturated – cannot dissolve more solute **Solubility Graph!!! [H+][OH-] = 1 x 10-14 Titration – process of neutralizing an acid or base Unsaturated – can dissolve more solute Supersaturated – too much dissolved