Honors Chemistry Guiding Questions Why do substances boil or freeze at different temperatures Why do we put salt on the roads in the winter Why does sweating cool us What is energy How do we measure energy ID: 1025960
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1. Unit 2:Matter and EnergyHonorsChemistry
2. Guiding QuestionsWhy do substances boil or freeze at different temperatures? Why do we put salt on the roads in the winter? Why does sweating cool us? What is energy? How do we measure energy?
3. units: L, dm3, mL, cm3 Matter Introductory Definitions (…pull out your vocab!)matter: anything having mass and volume mass: weight: volume: L3state of matter: the amount of matter in an object the pull of gravity on an object the space an object occupies solid, liquid, or gas
4. Solid, Liquid, Gas (a) Particles in solid (b) Particles in liquid (c) Particles in gas
5. composition: copper: water: properties: atom: a basic building block of matter what the matter is made of many Cu atoms many groups of2 H’s and 1 O describes matter what it looks like, smells like, etc. how it behaves ~100 diff. kinds Qualitative observations
6. Lr103No102Md101Fm100Es99Cf98Bk97Cm96Am95Pu94Np93U92Pa91Th90Lu71Tm69Yb70Er68Ho67Dy66Tb65Gd64Eu63Sm62Pm61Nd60Pr59Ce58He2Ne10Ar18Kr36Xe54Rn86At85I53Br35Cl17F9Po84Te52Se34O8Bi83Sb51As33N7Pb82Tc43Ta73Hg80Mt109Hs108Bh107Sg106Db105Rf104Ac89La57Hf72W74Re75Os76Ir77Rh45Ru44Mo42Nb41V23Li3Fr87Cs55H 1Na11K19Rb37Mn25Co27Pd46Au79Cd48Zn30Cu29C6B5Al13S16P15Si14Ge32Sn50Ag47Pt78= Internet link()Fe26Ni28Cr24Ti22Sc21Zr41Y39Ga31In49Tl81Mg12Ca20Sr38Ba56Ra88Be4Select an elementOther Physical DATAThe Periodic Table of ElementsRg111Ds110Cp112Uut113Fl114Uup115Lv116Uus117Uuo118
7. Elements contain only one type of atom 1. monatomic elements consist of unbonded, “like” atoms e.g., 2. polyatomic elements consist of several “like” atoms bonded togetherdiatomic elements: Fe, Al, Cu, He H2 O2 Br2 F2 I2 N2 Cl2 “HOBrFINCl = Hoberfinckle”“BrINClHOF = Brinklehoff”others: P4 or S8
8. Diatomic Elements, 1 and 7H2N2O2F2Cl2Br2I2
9. allotropes: different forms of the same element in the same state of matter OXYGEN CARBON oxygen gasozoneelementalcarbon graphite diamond buckyball (O2) (O3)
10. Allotropes of CarbonGraphite
11. Diamonds
12. Allotropes of CarbonC60 & C70“Buckyballs”“Buckytubes”BuckminsterfullereneBuckminster Fuller was known for designing geodesic domes, like Epcot Center
13. Allotropes of CarbonCarbon nanotubes
14. Allotropes of CarbonGrapheneSuper strong and super conductiveChem Matters Graphene Video
15. molecule: a neutral group of bonded atomsDescriptionChemical SymbolModel1 oxygen atom1 oxygen molecule2 unbonded oxygen atoms1 phosphorus atom1 phosphorus molecule4 unbonded phosphorus atomsOO22 OPP4Elements may consist of either molecules or unbonded atoms4 P
16. Compounds…contain two or more different types of atoms…have properties that are different from those of their constituent elementsNa (sodium): Cl2 (chlorine): explodes in water poisonous gas table salt (NaCl)
17. Atoms can be altered onlyby _______ meansMolecules can be alteredby ________ means(i.e., chemical reactions) nuclear chemical e.g., Dehydration of sugar C12H22O11(s) 12 C(s) + 11 H2O(g) Electrolysis of water 2 H2O(l) 2 H2(g) + O2(g) Atomic blast at HiroshimaUBaKrneutron“bullet”
18. Classifying Matter (Pure) Substances …have a fixed composition…have fixed propertiesELEMENTS COMPOUNDS e.g., e.g., Fe, N2, S8, U H2O, NaCl, HNO3 Pure substances have a chemical formulasulfur (S8)sodium chloride (NaCl)
19. Mixtures two or more substances mixed together …have varying composition…have varying properties The substances are NOT chemically bonded,and they…retain their individual propertiesTea, orangejuice, oceans,and air are allmixtures
20. Two Types of Mixtures1. homogeneous: (or solution) particles are microscopic; sample has the samecomposition and properties throughout;evenly mixed e.g., alloy: a homogeneous mixture of metalse.g., Kool Aid bronze (Cu + Sn) brass (Cu + Zn) pewter (Pb + Sn) salt water Oh Yeah!
21. Two Types of Mixtures (cont.)2. heterogeneous:different composition and properties in thesame sample; unevenly mixed e.g., suspension: settles over time e.g., tossed salad raisin bran paint snowy-bulb gifts
22. MATTERChart for Classifying Matter PURE SUBSTANCE MIXTURE ELEMENT COMPOUND HOMOGENEOUS HETEROGENEOUS Has a chemical formulaHas NO chemical formulaMade of 1 elementMade of 2 or more different elementsUnevenly mixedUniform or evenly mixed throughout (a solution)
23. AlikeDifferentDifferentTopicTopicDouble Bubble Mind Map
24. Mixture vs. Compound MixtureFixedCompositionBonds betweencomponentsCan ONLY beseparated bychemical meansVariableCompositionNo bondsbetweencomponentsCan beseparated byphysical meansAlikeDifferentContain two or moreelementsCan beseparated intoelementsInvolvesubstancesCompoundDifferentTopicTopic
25. Contrast… 24K GOLD 14K GOLD 24/24 atoms are goldelement pure gold 14/24 atoms are goldmixture of gold & other metalsAuhomogeneous mixturee.g., Au + Cu
26. Assume that human beings are12.1% C and 16.2% O.A. Brian Urlacher weighs 254 lb. How many lb of C and O are “in” Brian Urlacher?C:O:254 lb (0.121) = 254 lb (0.162) = 30.7 lb C 41.1 lb O B. If I have 19.7 lbs of C, how much do I weigh? 163 lbX =
27. X = 73 tall giraffesshort = 62 – 2743.5% of adult male giraffes aretaller than 5.34 m. A. There are 168 adult males in a particular herd. How many are taller than 5.34 m?B. In another herd, there are 27 adult males taller than 5.34 m. How many short males are in the herd?X = 0.435(168)X = 62 total males35 short giraffes
28. Every sample of NaCl tastes the same, melts at the same temp., and is 39.3% Na and 60.7% Cl by mass.Compound Composition All samples of a given compoundAlways have the same composition
29. Phosgene gas (COCl2) is 12.1% carbon,16.2% oxygen, and 71.7% chlorine bymass. Find # of g of each element in254 g of COCl2.C:O:Cl:254 g (0.121)= 30.7 g C 254 g (0.162)= 41.1 g O 254 g (0.717)= 182 g Cl
30. = 0.828A sample of butane (C4H10) contains 288 g carbonand 60. g hydrogen. Find…A. …total mass of sample B. …% of each element in butane C. …how many g of C and H are in a 24.2 g sample 288 g C + 60 g H82.8% C17 % H = 348 g % C == 0.17% H =C:H:24.2 g (0.828)= 20.0 g C 24.2 g (0.17)= 4.2 g H 24.2 g
31. A 550 g sample of chromium (III) oxide (Cr2O3)has 376 g Cr. How many grams of Cr and Oare in a 212 g sample of Cr2O3? 68.4% Cr% Cr =and31.6% OCr:O: 212 g (0.684)= 145 g Cr 212 g (0.316)= 67 g O chromium (III) oxide100 %
32. Oxygen (65%)Carbon (18%)Hydrogen (10%)Nitrogen (3%)Calcium (1.5%)Phosphorus (1.0%)Potassium (0.35%)Sulfur (0.25%)Sodium (0.15%)Magnesium (0.05%)Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)Elemental Analysis of Human Body (by mass %)
33. Elemental Analysis of Human Body (by # of atoms)Hydrogen (63%)Oxygen (24%)Carbon (12%)Nitrogen (0.58%)Calcium (0.24%)Phosphorus (0.14%)Sulfur (0.038%)Sodium (0.037%)Potassium (0.033%)Magnesium (0.0070%)Iron (0.00067%)
34. A sample of bronze contains 68 g copper and 7 g tinA. Find total mass of sampleB. Find % Cu and % SnC. How many grams of each element does a 346 g sample of bronze contain? 68 g Cu + 7 g Sn= 75 g 90.7% Cu% Cu =and 9.3% SnWe don’t know! (Bronze is a mixture and isn’t necessarilyalways 90.7% Cu and 9.3% Sn.)However, assuming these % are correct… Cu:346 g (0.907)= 314 g Cu (and 32 g Sn)
35. Separating Mixtures …involves physical means, or physical changes1. sorting: 2. filter: by color,shape,texture,etc. particle sizeis different Episode 5
36. filtration in the chemistry laboratory
37. filtration in the “real world”
38. Separating Mixtures (cont.) 3. magnet: 4. chromatography: one substance mustcontain iron some substances dissolvemore easily than others
39. Separating Mixtures (cont.) 5. density: “sink vs. float” perhaps use a centrifuge decant: to pouroff the liquid blood after high-speed centrifuging
40. Separating Mixtures (cont.) 6. distillation: different boiling points heat sourcethermometerwater in(cooler) water out(warmer) more-volatile substance mixturecondenser more-volatilesubstance, nowcondensed(i.e., the onewith the lowerboiling point)
41. No chemical reactionsare needed to separate mixtures;substances are NOT bondeddental amalgam
42. Properties of Matter CHEMICAL properties tell how a substance reacts with other substancesPHYSICAL properties can be observed without chemically changing the substanceEXTENSIVE properties depend on the amount of substance presentINTENSIVE properties do not depend on the amount of substance ONE OF THESEAND ONE OF THESE
43. P,Examples: electrical conductivity……………………..… reactivity with water………………………..... heat content (total energy)………………..… ductile: can be drawn (pulled) into wire….. malleable: can be hammered into shape… brittle……………………………………………. magnetism……………………………………… C,P,IIEP,IP,IP,IP,I
44. Physical and Chemical PropertiesExamples of Physical PropertiesBoiling point Color Slipperiness Electrical conductivityMelting point Taste Odor Dissolves in waterShininess (luster) Softness Ductility Viscosity (resistance to flow)Volatility Hardness Malleability Density (mass / volume ratio)Examples of Chemical PropertiesBurns in air Reacts with certain acids Decomposes when heated Explodes Reacts with certain metals Reacts with certain nonmetals Tarnishes Reacts with water Is toxic Ralph A. Burns, Fundamentals of Chemistry 1999, page 23Chemical properties can ONLY be observed during a chemical reaction!
45. The formation of a mixtureThe formation of a compoundChemical ChangePhysical Change
46. Physical & Chemical ChangesLimestone,CaCO3crushingPHYSICALCHANGECrushed limestone,CaCO3heatingCHEMICALCHANGEPyrexCO2CaOLime andcarbon dioxide,CaO + CO2
47. PyrexO2H2OPyrexH2O2Light hastens the decomposition of hydrogen peroxide, H2O2. The dark bottle in which hydrogen peroxide is usually storedkeeps out the light, thus protecting the H2O2 from decomposition.Sunlight energy
48. States of MatterLIQUID SOLID GAS ( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )( ( ) )vibratingtranslating;close togethertranslating quickly;far apart
49. Changes in State Energy put into systemEnergy removed from systemLIQUID GASSOLID freezingcondensationdepositionsublimationboilingmelting
50. Energy the ability to do work potential energy: kinetic energy: -- -- e.g., stored energy stored in bonds between atoms in food,energy of motion wiggling, translating,and rotating of particles -- “hot” gas particles movefaster, have more KE gasoline, batteries
51. Law of Conservation of Energy: 2 H2 + O2 2 H2O Eafter = Ebefore ++energy +WHOOF!
52. For the combustion of acetylene… PEreactantsPEproductsKEstopperheat, light, soundENERGYCO2 + H2OC2H2 + O2Energy is conserved.
53. Energy Changesendothermic change: system absorbs heat exothermic change: system releases heat -- -- Choose “endo” or “exo”…water boiling paper burning steam condensing CO2 subliming water freezing ice melting beaker feels cold beaker feels hot ENDO EXO EXO ENDO EXO ENDO
54. RP Energy endothermic exothermicRP EnergyACTIVATIONENERGY(most chemical reactions)(photosynthesis)CO2 + H2O + sunlight C6H12O6 + O2C + O2 CO2Reaction Coordinate Diagrams
55. The Mole Atoms are so small, it is impossible to count them bythe dozens, thousands, or even millions.To count atoms, we use the concept of the mole1 mole of atoms = That is, 1 mole of atoms = _________ atomsThe mole is the SI unitfor “amount of substance.”602,000,000,000,000,000,000,000 atoms 6.02 x 1023
56. How Big is a Mole? …about the size of a chipmunk,weighing about 5 oz. (140 g), andhaving a length of about 7 inches (18 cm).I meant, “How Big is 6.02 x 1023?”BIG.6.02 x 1023 marbles would cover theentire Earth (including the oceans) …to a height of 2 miles. 6.02 x 1023 $1 bills stacked face-to-face…and back …7.5 million times. (It takes light 9,500 years to travel that far) would stretch from the Sun to Pluto
57. For any element on the Periodic Table,one mole of that element(i.e., 6.02 x 1023 atoms of that element)has a mass in grams equal to the decimalnumber on the Table for that element. He2 4.003Ne1020.180Ar1839.948Kr3683.80Xe54131.29Rn86(222)1 mole of (i.e., 6.02 x 1023) helium atoms has a mass of 4.0 grams. 1 mol Ne = 20.2 g1 mol Ar = 39.9 g1 mol Kr = 83.8 g1 mol Xe = 131.3 g1 mol Rn = 222 g
58. 1 mol = 6.02 x 1023 particlesMOLE(mol)MASS(g)Particle(atoms)1 mol = molar mass (in g)Island Diagram
59. Island Diagram Problems1. How many moles is 3.79 x 1025 atoms of zinc? = 63.0 mol Zn1 mol6.02 x 1023 at.3.79 x 1025 at. 2. How many atoms is 0.68 moles of zinc? = 4.1 x 1023 at. Zn1 mol6.02 x 1023 at.0.68 mol.
60. 3. How many grams is 5.69 moles of uranium?5.69 mol1 mol238.0 g= 1,354 g U= 1.35 x 103 g U4. How many grams is 2.65 x 1023 atoms of neon? 1 mol= 8.9 g Ne20.2 g1 mol6.02 x 1023 at.2.65 x 1023 at. 5. How many atoms is 421 g of promethium?421 g1 mol145 g1 mol6.02 x 1023 at.= 1.75 x 1024 at. Pm