A.P. Chemistry Unit 1 Chapters 1*, 2, 3 Why take Chemistry? Purpose of AP Chem at CG? Introductory terms • Table groups Definition Review: Try to fill in 1. Chemistry 2. Chemical Property 3. Physical Property 4. Intensive property 5. Extensive property Terms to recognize 6. Element 7. ATOM 8. Compound 9. Molecule 10. Formula Unit TERMS 11. Pure substances 12. Chemical reaction 13. Physical change 14. Mixture 15. Homogeneous 16. Heterogeneous 17. Chemical symbol 18. Chemical formula More terms 19. Chemical Equation 20. Reactants 21. Products 22. Coefficients 23. Subscripts 24. Matter 25. Law of conservation of energy 26. Law of conservation of matter 27. Name Steps in the “Scientific Method” 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Asking a question Forming hypotheses Researching previously found information Designing experiments Conducting experiments / collecting data Determining variables: dependent and independent Organizing and analyzing data Stating conclusions Considering sources of error Communicating results Planning future experiments Classification of Matter ALL Matter Mixture Pure Substance Easily Separated Homogeneous Solutions Heterogeneous Always Homogeneous Element Compound Atoms Periodic Table Molecules or Crystals Formulaic Atoms Molecules Elements Compounds? 1. 2. 3. 4. 5. Aluminum foil Carbon Dioxide Zinc Graphite Helium 6. oxygen gas 7. sodium chloride 8. water 9. chlorophyll 10. nitrogen 1. 2. 3. 4. 5. E, A C, M E, A E, A E, A 6. E, M 7. C, “?M” 8. C, M 9. C, M 10. E, M Solid, Liquid, Gas (room temperature) 1. Ammonia 2. Gasoline 3. Graphite 4. H2O 5. Shaving cream 6. Aluminum 7. Ice cream 8. Helium 9. Bromine 10.Sugar Solid, Liquid, Gas (room temperature) 1. G 2. L 3. S 4. L 5. L & G …? 6. S 7. L 8. G 9. L 10. S Pure Substance or Mixture? 1. 2. 3. 4. 5. 6. 7. 8. Water Hydrogen Salt Tea Sodium Sugar Iron oxide concrete 9. Raisin cookie 10. Gatorade Pure Substance or Mixture? 1. 2. 3. 4. 5. 6. 7. 8. P P P M P P P M 9. M 10. M Chemical or Physical Change? 1. Dog is groomed 2. Child gets taller 3. Gas forms when Baking soda is mixed with vinegar 4. Pencil is sharpened 5. Paper burns 6. Leaves turn color 7. Ice melts 8. Sugar dissolves in water 9. Cookie bakes in oven 10. Cake mix is combined with water. Chemical or Physical Change? 1. 2. 3. 4. 5. 6. 7. P C C P C C P 8. P 9. C 10. P (?) Metric fundamental units • Kilogram • Meter • Second • mole • Kelvin • Coulomb Metric units for?.... 1. 2. 3. 4. 5. 6. Length mass area volume Density Weight and Force 7. Energy 8. particles 9. Pressure 10. Current 11. Potential 12. Power fundamentals?.... 1. 2. 3. 4. 5. 6. 7. yes yes yes yes yes Kg*m/s2 Kg*m2/s2 8. yes 9. Kg*m/s2 10. C/s 11. Kg*m2/Cs2 12. Kg*m2/s3 13. yes Metric units? • Fundamental? • Can you convert? • • • • • • • • Deci Centi Milli Kilo Nano Giga Micro Mega AP Chemistry Chapter 2 Atoms, Molecules and Ions John Dalton • English school teacher • 1766-1844 • Author of the Modern Atomic Theory • loved studying the weather • saw the applications for chemistry in his ideas about the atmosphere. • Proposed Atomic Theory: 1803 • Dalton's theory was presented in New System of Chemical Philosophy (1808-1827). John Dalton • Was colorblind • Daltonism • His eyes were used to prove it is a brain disorder Postulates of Dalton’s atomic theory Matter is made of atoms which stay the same during a chemical change. An element is a substance made of one type of atom, each of which has the same properties. A compound is matter made of two or more elements combined in fixed proportions. A chemical reaction involves rearrangement of atoms into new substances, but no loss or gain of any atoms. Law of definite proportions • Molecules of the same compound are all the same. The same elements can make many different compounds. Atomic Structure Modern Theory Says… • Atoms are made of: • Protons • neutrons • electrons • a small dense nucleus of protons and neutrons and surrounding electrons. Famous experiments leading to this view of the atom: • Joseph John Thomson: • The Cathode Ray Tube Experiment (Cambridge; 1897); • discoverer of the electron, Nobel Prize Winner. The Cathode Ray Tube and Thomson’s Plum Pudding atom Robert Millikan • The Oil Drop Experiment (USA, 1909) • measured charge on an electron • calculated the mass of electrons. Millikan’s Experiment • Used calculation to determine the charge on each suspended droplet • All were multiples of 1.6x10-19 Coulomb Ernest Rutherford • Studied Gold Foil Experiments by Geiger and Marsden (1911) • atoms are mainly empty space with a small, massive, dense, positively charged nucleus. • Also discovered the proton. Gold Foil Experiment Video? • Led to the idea of a nuclear atom • Led to the idea that atoms are mainly made of empty space. Modern Atomic theory • the atom consists of 40 fundamental particles. • The electron is a quark, but the proton and the neutron are not. ISOTOPES • Atoms of the same element that have different masses (different # of neutrons in the nucleus). ISOTOPES TO KNOW • The three isotopes of hydrogen: • Protium = H-1 • Deuterium = H-2 Water made with this is called heavy water. • Tritium = H-3 and is radioactive! AZ symbols • A: mass #, nuclear particles, P+N • Z: atomic #, nuclear charge, P • Neutrons =? • X = element symbol Write an “AZ” nuclide symbol for • strontium 90 • silicon 30 • radon 226 Atomic number vs mass number Protons : nuclear charge vs protons + neutrons : number of nuclear particles • Atomic weight vs atomic number ~Weight of protons, neutrons, electrons Vs Proton number: nuclear charge Atomic particles Atomic Weights • All relative to the Carbon-12 isotope • Carbon-12 is the mass standard • One mole of carbon 12 = 12 grams Atomic Weights • Represent: average mass of isotopes and their percent composition in nature. Measuring atomic weight • Units are “amu” • Atomic mass units • One mole of amu = 1 gram Measuring the weight of atoms By Mass spectrometry. • An unknown is compared to a known sample ( the standard). • Particles are accelerated through a gas and bent by a magnetic field. • The curvature of their pathway is measured and mass is calculated. • F=Bvq. Mass Spec and examples • See worksheet Example • Given data for Chromium, determine its average atomic weight. • Isotope Mass Frac. Abundance • Cr-50 49.9461 0.0435 • Cr-52 51.9405 0.8379 • Cr-53 52.9407 0.0950 • Cr-54 53.9389 0.0236 51.9959 u Copper’s two isotopes are mass numbers 63 and 65: What percent abundance is each if the average atomic mass is 63.5? No calculator! • What is the mass in grams of a mole of titanium atoms? • What is the mass of one atom of Ca-40? • Answer in g and amu History of the periodic table Dmitri Mendeleev (Russia) • Wrote periodic law • Chart based on atomic weights. John Newlands, Great Britain • law of octaves. • ridiculed b/c of inconsistencies Julius Lothar Meyer, Germany • periodic law around the same time as Mendeleev. • not credited as Mendeleev b/c ?? Predictions undiscovered….. Henry Mosely • 1887-1915 • Studied with Rutherford, • measured nuclear charge / atomic number of elements. Henry Mosely • Reordered periodic table by at.# and it is better Henry Mosely • Volunteered for service in WWI. Was a signal officer for the British Army and killed in action at Gallipoli in 1915. The Periodic Table • Periods: • 7 horizontal Rows • Families / Groups: 18 vertical columns Sketch and label Binary • Made of two elements. • Examples? Molecular • Made of molecules • Nonmetal atoms making compounds • Covalent: shared electrons. Ionic • Made with a metal ion or ammonium and an anion….. Ionic or Molecular? • • • • • Na2CO3 C4H10 MgSO4 Al2 (SO4)3 KF • CuBr2 • H2 O • Li2O • NH4I • RbClO Making ions • Cations vs anions • Only changes in electrons Formula unit vs molecule • Ionic vs not ionic • Low ratio of ions vs formula of particle Ionic charges • Metals vs nonmetals • Metals make cations • Nonmetals make anions Ion names • Metals vs nonmetals • The –ide ending for nonmetals Nomenclature practice time • Use the ion sheets • Use the flowchart • Follow the rules • Practice! Name these Compounds 1. 2. 3. 4. 5. 6. HClO HF H2O2 PbCrO4 LiC2H3O2 CO 7. CdI2 8. N2O5 9. CuSO4 10. SrBr2 11. H3PO4 12. Ca(NO3)2 Name these Compounds 1. 2. 3. 4. 5. 6. Hypochlorous acid Hydrofluoric acid Dihydrogen dioxide Lead II chromate Lithium acetate Carbon monoxide 7. 8. 9. 10. 11. 12. Cadmium iodide Dinitrogen pentoxide Copper II sulfate Strontium bromide Phosphoric acid Calcium nitrate Write Formulas for these Compounds 1. 2. 3. 4. 5. 6. Cobalt III hydroxide Barium phosphate Magnesium chloride Aluminum iodide Sodium oxide Perchloric acid 7. Nitrous acid 8. Oxalic acid 9. Hydrobromic acid 10.Diphosphorous pentoxide 11.Dinitrogen monosulfide 12.Silver carbonate Write Formulas for these Compounds 1. 2. 3. 4. 5. 6. Co(OH)3 Ba3(PO4)2 MgCl2 AlI3 Na2O HClO4 7. HNO2 8. H2C2O4 9. HBr 10. P2O5 11. N2S 12. Ag2CO3 Organic Chemistry Intro • carbon based with hydrogen and oxygen mainly. • Hydrocarbons: C and H only • Alkanes: Hydrocarbons with only singly bonded carbon atoms. 1st rule: C bonds 4 times • • Alcohols: Have an -OH functional group • Isomers: Molecules with the same formula but different structures • R: general symbol for a carbon chain • If R = __Carbon, it is called: • 1 Carbon = meth(yl) • 2 Carbons = eth(yl) • 3 Carbons =prop(yl) • 4 Carbons =but(yl) • 5 Carbons =pent(yl) • 6 Carbons =hex(yl) • 7 Carbons =hept(yl) • 8 Carbons =oct(yl) • 9 Carbons =non(yl) • 10 Carbons =dec(yl) ORGANIC NOMENCLATURE Draw… and decide if isomers exist. • Propane • 1-butanol • pentane Name each. If they have any isomers, name one of them too. • CH3CH2CH2CHOHCH2CH2CH2CH2CH3 • CH3CH2CH2CH2CH2CH3 • CH3OH STOICHIOMETRY • Using a balanced equation to make theoretical predictions. • Beqs show COM! Simple reactions • Combination (synthesis) • Smaller reactants make a more complex product. Simple Reactions • Decomposition • A reactant forms simpler products Classify a-e • Combination • a c • Decompostion • b d e Combustion • Hydrocarbon and oxygen gas reactants • CO2 and H2O products Combustion: write reactions • Octane • 2-Hexanol • 3-Heptanol “weight” Units • Molecular or formula weight: u or amu • Molar mass: g/mol Formula weight or molecular weight of: • • • • • • • • A. carbon dioxide 44.0 amu B. water 18.0 amu C. oxygen gas 32.0 amu D. Table salt 58.5 amu Molar Mass of: • • • • • • • • A. carbon dioxide 44.0 g/mol B. water 18.0 g/mol C. oxygen gas 32.0 g/mol D. Table salt 58.5 g/mol Mole • 6.02x1023 • Used to count particles • A mole of miniature marshmallows would cover the USA to a depth of 600 miles. Mole Relationships • 1 mole = 6.02x1023 at or mc or fu • 1 gram = 6.02x1023 amu • 1 mole = S at wt of any formula (g) • 1 mole gas (STP) = 22.4 L Practice Mole Calculations 1. 0.0365 g 2. 1.0x1024 atoms 3. 23.6 mol 4. 1.1x10-21 amu 5. 250. Liters 6. 42.1%C, 6.4%H, 51.5%O 7. 51.9 %N • Determine the empirical and molecular formula of a compound found by combustion to contain 39.9% Carbon, 6.7% hydrogen and 53.4% oxygen. The molecular weight of the compound is 120 amu. • Empirical: CH2O • Molecular: C4H8O4 Example Problem • Pretend to have 100 grams …. Or…. • If grams are given, use them! • Change grams to moles for each element. • Look at mole ratios to work out lowest whole number subscripts. • Use known molar mass to find molecular formula with integer multiplier. Problem Solving • A sample of a compound is found to contain 17.5 g Na, 39.7 g Cr and 42.8 g O. What is its empirical formula? • Na2Cr2O7 • Sorbic acid is added to food as a mold inhibitor. Its composition is 64.3% C, 7.20% H , and the rest oxygen. Its molecular weight is 112 u. What is the molecular formula for sorbic acid? • C6H8O2 •Challenge Problem, AP level An organic acid contains only C, H and O. A 12.72 mg sample of the acid is completely burned in oxygen. It yields 18.63 mg of carbon dioxide and 7.62 mg of water. What is the mass percentage of each element in the organic acid? What’s the empirical formula? • Review: Write an equation for the formation of carbon dioxide from its elements. • C + O2 ----> CO2 • How many grams carbon are needed to produce 150. grams of carbon dioxide? • 40.9 grams • Stoichiometry uses the balanced equation ratios. • Balanced equation coefficients are about particle to particle ratios. • Coefficients mean moles or atoms/molecules/formul a units • Or (by thinking of Avogadro’s Hypothesis) volumes(any units) for gaseous substances. Problem Solving AMEDEO AVOGADRO Stoichiometry • Write an equation for the reaction of sodium in water. • 2Na + 2H2O ---> 2Na+ + 2OH- + H2 • How many molecules of hydrogen gas are produced by the reaction of 0.25 grams of sodium METAL? • 3.3x1021 molecules Stoichiometry • Write the equation for the dehydration of ethyl alcohol and butanoic acid into ethyl butyrate, an ester. • C2H5OH + C3H7COOH ---> C3H7COOC2H5 + H2O • How many grams of water can be made from 8.22x1023 molecules of ethyl alcohol (ethanol)? • 24.6 grams Ethyl butyrate is the odor of pineapples. Limiting Reagents and Percent Yield • Write an equation for the synthesis of aluminum chloride. • 2Al + 3Cl2 ---> 2AlCl3 • If 3.00 g Al react with 13.0 g Cl2, how much AlCl3 can be produced? Use an IRF box 2 Al I Initial moles R reacted moles F final moles 3g= 0.111 moles + 3Cl2 ------> 2AlCl3 13 g = 0.183 moles 0 moles • Determine the limiting reagent. • Use initial moles compared to how many are required for each reaction. • Low number limits the process. Use an IRF box 2 Al I Initial moles R reacted moles F final moles 3g= 0.111 moles * Limiting reagent!! + 3Cl2 ------> 2AlCl3 13 g = 0.183 moles 0 moles Use an IRF box 2 Al I Initial moles R reacted moles F final moles 3g= 0.111 moles ** All 0.111 moles used 0 moles left over + 3Cl2 ------> 2AlCl3 13 g = 0.183 moles 0 moles Fill in “R” Row • Mole ratios in “R” row must match the reaction coefficient ratios. • The next coefficient divided by LR coefficient, multiplied by limiting moles ---> “R” moles Use an IRF box 2 Al I Initial moles R reacted moles F final moles 3g= 0.111 moles 0.111 moles + 3Cl2 ------> 2AlCl3 13 g = 0.183 moles 0 moles 0.167 moles 0.111 moles Fill in “F” row • Subtract for reactants, add for products • Once the box is filled in with moles, any question can be answered. Use an IRF box 2 Al I Initial moles R reacted moles F final moles + 3Cl2 ------> 2AlCl3 13 g = 0.183 moles 0 moles 0.111 moles 0.167 moles 0.111 moles 0 moles 0.016 moles 0.111 moles 3g= 0.111 moles Now solve the problem! • If 3.00 g Al react with 13.0 g Cl2, how much AlCl3 can be produced? • 14.8 grams • If 12.0 grams is recovered, what is the percent yield? • 81.0% Problem Solving • Thinking of the balanced equation as a recipe might help. • Determine how many times the reaction “recipe” can be carried out with each amount of moles. • Reactant that can make the fewest “batches” is the limiting reagent. Limiting Reagent and Percent Yield Lithium metal • Write an equation for the synthesis of lithium hydroxide from lithium oxide and water. • Li2O + H2O ---> 2 LiOH • If 42.0 grams lithium oxide react with 20.0 grams water, how much LiOH can be produced? • 53.1 grams • If 45.0 grams are obtained, what is the percent yield of the experiment? • 84.7% • Write an equation for the preparation of hydrocyanic acid and water from ammonia, methane and oxygen. • 2NH3 + 3O2 + 2CH4 --> 2HCN + 6H2O • How many grams of HCN can be obtained from the reaction of 25.0 grams ammonia, 75.0 grams oxygen and 25.0 grams methane? • 39.7 grams • If 11.0 grams HCN is obtained, what is the percent yield of the reaction process? • 27.7 % Limiting Reagents and %Yield That’s the end of Ch. 3! • Mole day is coming SOON! • Make the moleata! • Talk to all other classes about donations for mole day? Mole Day • CG Chemistry T-Shirt Ideas T-shirt Ideas Build the Moleata! A.P. Chemistry Chapter 4 Chemical Reactions: An Introduction I. Ionic Solutions • Deionized water vs. tap water, bath water, lake water, ocean water? • Ions! Svante Arrhenius • Svante August Arrhenius b. Uppsala, Sweden, February 19, 1859 • son of Svante Gustaf and Carolina • educated at the Cathedral school; Showed an aptitude in mathematics and physics. • 1876: University of Uppsala: mathematics, chemistry and physics. • 1881: Stockholm’s Academy of Sciences. • twice married - in 1894 to Sofia Rudbeck, (one son) and 1905 to Maria Johansson (one son and two daughters) • died at Stockholm, October 2, 1927, and is buried at Uppsala. Ionic solutions are ..... • electrolytic • Capable of conducting electricity • Many ionic solids are electrolytic in water. • the ions = electrolytes (particles that conduct electricity) What ions are found in a solution of... • • • • KOH? CaCl2? (NH4) 2SO4? Write equations for what these compounds do in water. • KOH (s) --> K+ (aq) + OH- (aq) • CaCl2 (s) --> Ca2+ (aq) + 2Cl- (aq) • (NH4) 2SO4 (s) ---> 2NH4+ (aq) + SO42- (aq) Nonelectrolytic • Make no ions (electrolytes) in solution. substances • • • • • • Examples: sucrose, C12H22O11 methanol, CH3OH urea, NH2CONH2 antifreeze, HOC2H4OH All are molecular Dissolve but do not make ions • C12H22O11 (s)---->C12H22O11 (aq) • CH3OH(l) ----->CH3OH (aq) • NH2CONH2 (s)----->NH2CONH2 (aq) • HOC2H4OH (l)----->HOC2H4OH (aq) Strong and Weak Electrolytes • refers to degree (%) of ionization of solute. • Acids and bases are described as strong or weak. Strong vs. Weak Acids • Strong acids ionize 100% • Weak acids ionize only partially • • • • • • • nitric Students must Know perchloric the 6 strong acids sulfuric hydrochloric hydrobromic Hydroiodic Write equations showing what each strong acid does in water. The Strong Acids in Water • • • • • • Nitric HNO3 ---> H+ + NO3Perchloric HClO4 ---> H+ + ClO4Sulfuric H2SO4 ---> 2H+ + SO42Hydrochloric HCl ---> H+ + ClHydrobromic HBr ---> H+ + BrHydroiodic HI ----> H+ + I- Dilute vs. Concentrated Solutions • refers to the amount dissolved per volume of solution. • dilute solutions: small amount dissolved. • Concentrated: more dissolved Writing Chemical Equations • can be done: • A. molecularly: show the whole mixture. • B. Ionically – complete ionic: indicates any electrolytes in mix – Net ionic: only shows species that changed. • AP CHEM: requires net ionic equation writing. • two aqueous solutions are mixed and one of the products is insoluble. • Aqueous: Dissolved in Water. • Precipitate: insoluble species. • Spectator Ions: in the mixture but do not take part in a reaction. I. Precipitation Reactions • SOLUBLE OR NOT? • Know: Solubility rules of ionic compounds..... page 136. • Knowing the solubility song / chart helps. Examples: Write the net ionic reactions! • 1. Potassium Chloride and Silver nitrate react in aqueous solution. • Net ionic: Cl- + Ag+ ----> AgCl • 2. Ammonium sulfate and calcium chloride react in aqueous solution. • Net ionic: Ca2+ + SO42- ----> CaSO4 • 3. Sodium carbonate and copper II sulfate react in aqueous solution. • CO32- + Cu2+ -----> CuCO3 More Practice. What will happen when the following mix? • NiCl2 and Na3PO4 • NaCl and Fe(NO3)2 • Al2(SO4)3 and KOH • Pb(C2H3O2)2 and NH4Cl Combustion: burns in O2 • hydrocarbons • Products always CO2 and H2O(l) • exothermic • Heat makes H2O vaporize. • Recognize some organic alkanes and alkenes, alkynes and alcohols. • Octane • 2-Hexene • 1-butyne • 3-Heptanol Equations to Balance Acid-Base Basics • Taste, feel ? • pH ranges ? • Ions they make in solution ? • Household examples of each • Page 139 The Strong Acids in Water • • • • • • Nitric HNO3 ---> H+ + NO3Perchloric HClO4 ---> H+ + ClO4Sulfuric H2SO4 ---> 2H+ + SO42Hydrochloric HCl ---> H+ + ClHydrobromic HBr ---> H+ + BrHydroiodic HI ----> H+ + I- The Strong Bases in water: • LiOH • NaOH • KOH LiOH ---> Li+ + OHNaOH ---> Na+ + OHKOH ---> K+ + OH- • Ca(OH)2 • Sr(OH)2 Ba(OH)2 Ca(OH)2 ---> Ca2+ + 2OHSr(OH)2 ---> Sr2+ + 2OHBa(OH)2 ---> Ba2+ + 2OH- Acid and Base Definitions Arrhenius Acids contain hydrogen and make hydrogen ions in water. Bases contain hydroxide and make hydroxide ions in water. Bronsted and Lowry acids and bases: Proton donors and proton acceptors. Indicators to know • Indicators are molecules that change colors at different pH levels. • phenolphthalein • Litmus • Methyl red • Others? Reactions of Acids/Bases • Learn to Write Net ionic equations for many examples! Neutralization reactions • acid + base water + salt. • salt: metal cation combined with an anion (often soluble in water) • General Equation • HA + MOH -----> H2O + MA • make examples…to net ionic Some Salts + acids gases. Carbonates + Acids ----> carbon dioxide, water and a salt. General Equation MCO3 + HA ----> H2O + CO2 + MA Write examples….. To net ionic. Demo and test for gas: Acetic acid and sodium (bi)carbonate Carbonates and Acids • Sulfites + Acids -----> sulfur dioxide, water and a salt. • General: • MSO3 + HA -------> H2O + SO2 + MA • examples: Write net reactions. • SO2 gas…. Stinky, irritating Sulfites and Acids Sulfides and Acids • A sulfide reacts with an acid to produce hydrogen sulfide gas and a salt. • General: • MS +HA --> H2S + MA • examples • test for gas? One Base Reaction • Decompostition of Hydroxides • MOH MO + H2O • Examples….. Oxidation and Reduction • Aka single displacement, synthesis or decomposition reactions. • electrons exchanged / atoms change oxidation states (charges). Define: Oxidation and Reduction • Oxidation: the loss of electrons • Reduction: The gain of electrons • LEO says “GER” Rules for deciding Oxidation State: • Elements alone have an ox. state of zero. • H is always 1+, unless it is with a metal as a hydride. • O is always 2- unless it is in a (rare) peroxide: H2O2, Li2O2, K2O2, or Na2O2. • All common /main group metals keep their periodic pattern charge. • Other semi and nonmetal elements’ oxidation states are determined last. • Sum of ox. States = charge on species. Tell each elements’ Oxidation State: 1. H3PO4 2. KNO3 3. Ca(NO2)2 4. BrO2 5. BrO36. BrO4 7. CH4 8. NH4Cl 9. Cl2O 10.N2O 11.NO 12.NO2 13.P2O5 14.KMnO4 15.Fe2(SO4)3 16.Na2C2O4 Types of “redox” reactions • Synthesis / Combination reactions • Decomposition Reactions • “single replacement” reactions • Combustion reactions • Other complex reactions What is oxidized, what’s reduced? • Copper nitrate solution reacts with zinc metal to make aqueous zinc nitrate and metallic copper. • Lithium metal reacts with a cobalt II chloride solution to make metallic cobalt and aqueous lithium chloride. What is oxidized, what’s reduced? • Ca + O2 ---> CaO • HgCl2 ----> Hg + Cl2 Will redox occur? Using the “Activity Series” • See the AP pages for the reduction potential list. What is reduced and what is oxidized? What are Ox. And Red. Agents? Write 1/2 reax. • Examples: • iron nail in copper sulfate. • Aluminum foil in tin II chloride solution. • Copper wire is placed in silver nitrate solution. CH. 19, section 1 • Balancing complex redox reactions in acid/base environments Last Topic: Solution Chem/Stoich “Volumetric Analysis” Measuring Concentration of Solutions • can be done in several different ways, including.... • Molarity • moles dissolved per liter of solution. • Molality: moles dissolved per kilogram of solvent • Mass percentage: mass of solute compared to mass of solution. • Mole fraction: moles dissolved compared to moles of total solution particles. Other Concentration Definitions Molarity Equation • M=n V M = Molarity n = moles dissolved solute V = volume of solution in liters Molality Equation • m=n • kg • m = molality • n = moles dissolved solute • kg = mass of solvent in kilograms. Mass Percent Equation • Mass of solute___ • Mass of solution • Express concentration as a percentage. • Any units for mass will do. Mole Fraction Equation • Moles of solute ________________ • Moles of solute + moles of solvent • Express result as a decimal number Practice: Molarity Problems • What is the molarity of a solution containing 34.2 grams of sucrose in 2.00 liters of solution? • 0.0500 M • What volume of 0.65 M HCl holds 3.0 grams of HCl? • 0.126 L or 126 mL Molarity and Dilution Problems • What mass of silver nitrate must be added to a flask to make 500. mL of 0.025 M solution? • 2.1 g • How many mL of 4.00 M acetic acid are needed to make 500. mL of 1.00 M solution? • 125 mL More Problems! • How many mL of 8.4 M KNO3 are needed to make 3.00 Liters of 2.5 M solution? • 890 mL • Suppose 200.mL of water are added to 400.mL of 1.20 M HNO3. What is the molarity of the resulting mixture? • 0.800 M • A 1.000 L sample of polluted water was analyzed for lead II ion by adding excess sodium sulfate to it. The mass of lead II sulfate precipitating was 220.0 mg What is the mass of lead in the water? • 150.3 mg • What would be the concentration of lead in the water? • 0.000725 M Stoichiometry with Molarity = Quantitative Analysis Solution Stoich • A flask contains water mixed with some HCl. The solution is titrated with 0.225 M KOH until a pH of 7 is reached. 15.20 mL of the KOH solution are needed. What is the mass of the HCl in the flask? • 0.125 grams Solution concentrations • If 35.0 grams of potassium nitrate are dissolved in 55.0 grams of water, the solution has a density of 1.108 g/mL. Determine the molarity, molality, mass%, and mole fraction concentration values of the solution. Learn to balance complex redox reactions: separate note page Include Ch. 19 section 1 problems with the chapter 4 problem set. Booknotes: not required for 19.1 Chemical or Physical Property? #1-7 1. 2. 3. 4. 5. 6. 7. It’s a liquid The pH is 12 It burns in air It tastes sweet It is green It weighs 5 lbs. It bubbles in acids Chemical or Physical Property? #1-7 1. 2. 3. 4. 5. 6. 7. P P C P (?) P P C Intensive vs. Extensive Properties? 1. 2. 3. 4. 5. 6. 7. Its mass is 50 g. It dissolves in oil. Its density is 1.5g/ml It is 6 inches long It conducts electricity It is acidic It is at room temperature. Intensive vs. Extensive Properties? 1. 2. 3. 4. 5. 6. 7. E I I E I I E Homogeneous or Heterogeneous? 1. 2. 3. 4. 5. 6. 7. 8. Concrete Jello Muddy water Diamond Hair Children in a class Tossed salad milk Homogeneous or Heterogeneous? 1. 2. 3. 4. 5. 6. 7. 8. He Ho He Ho He He He Ho Element, Compound or Mixture? 1. 2. 3. 4. 5. 6. 7. 8. C E C M E C C M 9. M 10. M Name these elements 1. 2. 3. 4. 5. 6. 7. Sb As Ni Fe Zr Ra Au 8. Na 9. Sr 10. Ag 11. Ba 12. P 13. F 14. Mg Name these elements 1. 2. 3. 4. 5. 6. 7. antimony arsenic nickel iron zirconium radium gold 8. sodium 9. strontium 10. silver 11. barium 12. phosphorus 13. fluorine 14. magnesium Write symbols for these elements 1. 2. 3. 4. 5. 6. 7. Aluminum Tin Rubidium Argon Helium Neon uranium 8. lead 9. potassium 10. calcium 11. zinc 12. chlorine 13. copper 14. tungsten Write symbols for these elements 1.Al 2. Sn 3. Rb 4. Ar 5. He 6. Ne 7. U 8. Pb 9. K 10. Ca 11. Zn 12. Cl 13. Cu 14. W Solubility Song • Sing • Make a Chart What is the chemistry of a soluble ionic compound? Solubility Quiz: Soluble or not? 1. Iron II hydroxide 2. Potassium phosphate 3. Barium nitrate 4. Strontium sulfate 5. Calcium chloride 6. Silver acetate Solubility Quiz: Soluble or not? 1. 2. 3. 4. 5. 6. not sol sol not sol not Name two solutions with soluble salts that would combine to form the precipitates in #1, 4 and 6 Ions to Know • Thoughts on patterns What is the common ionic charge for each element? 1. 2. 3. 4. 5. 6. 7. calcium argon potassium nitrogen chlorine aluminum oxygen What is the common ionic charge for each element? 1. 2. 3. 4. 5. 6. 7. 2+ 0 1+ 313+ 2- Name these ions • • • • • • • SO42NO3PO33C2H3O2NH4+ S2O32C2O42- Name these ions • • • • • • • Sulfate Nitrate Phosphate acetate ammonium thiosulfate oxalate Write formulas for these ions • • • • • • • Carbonate Nitrite sodium iodite sulfite sulfide bromate Write formulas for these ions • • • • • • • CO32NO2Na+ IO2SO32S2BrO3- What is the charge on these ions? • • • • • • • PO3 N AsO4 ClO2 S2O8 NH4 IO4 Something New…in Chapter 1 • Antoine LaVoisier 1743-1794 French Chemist father of modern chemistry At age 28 married 13-year-old Marie-Anne who translated from English for him and illustrated his books; she was well educated in chemistry herself. •burned P and S in air, and proved the products weighed more than the reactants but the weight gained was lost from the air. •Thus established the Law of Conservation of Mass. •1778: demonstrated the "air" responsible for combustion; named this portion of air oxygen and the other part of air “azote” (Greek for no life). •discovered that hydrogen combined with oxygen to produce water. Antoinne LaVoisier •1787: invented the system of nomenclature still used today. •1789: published the first modern chemical textbook, with his theories: •a clear Law of Conservation of Mass •There is no such thing as phlogiston •a list of elements, including oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc, and sulfur….. but also included light and caloric Lavoisier: "I have tried...to arrive at the truth by linking up facts; to suppress as much as possible the use of reasoning, which is often an unreliable instrument which deceives us, in order to follow as much as possible the torch of observation and of experiment." Phlogiston Theory • Ancient Greeks thought there were four substances in the world: E,A, F, W • In the 1600’s Johann Becher added to the list: Phlogiston is a 5th “element”… it’s in any substance that burns! •LaVoisier •worked as a tax collector •beheaded during the French revolution for using public money to fund his research. LaVoisier beheaded in France. A Word about ENERGY • What is it? • Law of Conservation of Energy Energy:part of chemical reactions • Energy is required to break bonds. • Energy is released as bonds form. • This is true in all physical and chemical changes. Reactions and Energy • Endothermic • Exothermic • More about NRG in later chapters. 9. What is the % Ag in your alloy? Compare the percent (what is your error%) you got to the theoretical value for the % Ag in dimes made before 1950. Suggest an error to account for the difference. Choose one with the correct direction. Results of the atomic theory • It yields definitions of: • Elements • Compounds • Chemical Reactions Dalton’s Postulates lead to two laws: • Conservation of Mass • Multiple Proportions:If two elements form more than one compound, the mass ratios of one of the elements in one compound to the same element in the other compound is always in a small whole number ratio. • Think of benzene and methane Mendeleev • Born in Siberia 1834 • Youngest of 14 children. • Hated everything in school except science. • Father died when he was 2, mother favored him as a student and child, she died after he got admitted to university at age 15. Mendeleev • In 1855 was told he had two years to live, probably had tuberculosis. • Worked as a professor of chemistry at St. Petersburg, Russia • Organized known elements according to their properties and thus discovered the periodic law. Mendeleev • Meyer also discovered a periodic law, but Mendeleev published first. • Was a talented and popular public speaker • Married Feozva, had two children… they did not get along. Divorced her and married Anna, with whom he had four children. • The Czar looked the other way on his “bigamy” Mendeleev • His periodic law was most accepted after it was shown his predictions of the existence of other elements were correct. • Eka-silicon and two others were discovered. • Died in 1907 at the age of 73. Molecular vs. Empirical formula • Molecular formula is the real formula for a compound • Empirical formula is the lowest ratio of elements in the compound. • Example: • ethylene glycol is C2H6O2 (molecular) • empirical formula is CH3O (lowest ratio) Structural Formula • Arrangement of the atoms in a formula to show what shape, function or type of molecule it is. • H-O-H CH3COOH • Many organic molecules are frequently written structurally. Organic Carbon Chain Classes • Alkanes • Alkenes • Alkynes The End of Chapter 1&2 notes • Time really matters. • T-shirt? Submit ideas Asap • Mole Day volunteers needed: make a moleata, run a contest. A.P. Chemistry: Chapter 3 • Calculations with Chemical Formulas and Equations What is a Mole?