Unit 2: Matter and Energy

1. Honors Chemistry Unit 2: Matter and Energy

2. 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?

3. L3 Matter Introductory Definitions (…pull out your vocab!) matter: anything having mass and volume the amount of matter in an object mass: the pull of gravity on an object weight: volume: the space an object occupies units: L, dm3, mL, cm3 state of matter: solid, liquid, or gas

4. Solid, Liquid, Gas (a) Particles in solid (b) Particles in liquid (c) Particles in gas

5. composition: what the matter is made of water: copper: many groups of 2 H’s and 1 O many Cu atoms properties: describes matter what it looks like, smells like, etc. how it behaves Qualitative observations atom: a basic building block of matter ~100 diff. kinds

6. 1 H 56 110 38 36 68 81 112 20 67 113 66 97 12 65 4 64 19 26 22 54 105 6 104 90 94 88 91 31 59 60 99 49 39 115 58 116 98 101 89 41 102 117 10 21 103 18 114 93 63 70 111 2 29 71 72 35 17 9 78 84 52 47 34 108 8 83 28 51 33 7 14 82 43 15 16 80 109 13 57 32 85 118 86 24 74 75 48 76 77 79 45 44 46 42 41 30 23 50 107 27 106 11 5 55 87 25 3 37 Uus Es Md No Tb La Xe O Ac Cf Te Eu Yb Pu Np Pa Th Lu Er Ho Dy Gd Po Hf Bk Se Db Os Nd Tc Sb Pb Hg Mt Hs Bh Bi N As Sg Lr Rf Cs Fr Li V Nb Mo Ru Rh Ir Re Pr Pd He In Ag Ga Pt Y Fe Rb Ni Cr Zr Tl Ce Al Ds Cp Au Lv Cd Mn Co Fl Zn Cu Sn Ti Mg Ar Kr K Rn At Br Cl F Na W Ne Sc Be C Ra B Ba Sr S P Ca Si Rg Ge Uup Uuo Uut 53 I 73 Ta 62 61 69 Sm Pm Tm 96 100 92 95 Cm Fm U Am The Periodic Table of Elements Select an element ( ) = Internet link Other Physical DATA

7. contain only one type of atom Elements 1. monatomicelements consist of unbonded, “like” atoms e.g., Fe, Al, Cu, He 2. polyatomicelements consist of several “like” atoms bonded together diatomicelements: H2 O2 Br2 F2 I2 N2 Cl2 “BrINClHOF = Brinklehoff” “HOBrFINCl = Hoberfinckle” others: P4 or S8

8. Diatomic Elements, 1 and 7 H2 O2 F2 N2 Cl2 Br2 I2

9. allotropes: different forms of the same element in the same state of matter OXYGEN CARBON oxygen gas (O2) elemental carbon graphite ozone (O3) buckyball diamond

10. Allotropes of Carbon Graphite

11. Diamonds

12. Allotropes of Carbon C60 & C70 “Buckyballs” “Buckytubes” Buckminsterfullerene Buckminster Fuller was known for designing geodesic domes, like Epcot Center

13. Allotropes of Carbon Carbon nanotubes

14. Allotropes of Carbon Graphene Super strong and super conductive

15. molecule: a neutral group of bonded atoms O O2 2 O P P4 4 P Elements may consist of either molecules or unbonded atoms

16. Compounds …contain two or more different types of atoms …have properties that are different from those of their constituent elements Na (sodium): explodes in water table salt (NaCl) Cl2 (chlorine): poisonous gas

17. neutron “bullet” U Ba Kr Atoms can be altered only by _______ means nuclear Molecules can be altered by ________ means chemical (i.e., chemical reactions) Atomic blast at Hiroshima e.g., Dehydration of sugar C12H22O11(s) 12 C(s) + 11 H2O(g) Electrolysis of water 2 H2O(l) 2 H2(g) + O2(g)

18. Classifying Matter (Pure) Substances …have a fixed composition …have fixed properties ELEMENTS COMPOUNDS e.g., Fe, N2, S8, U e.g., H2O, NaCl, HNO3 sulfur (S8) sodium chloride (NaCl) Pure substances have a chemical formula

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 properties Tea, orange juice, oceans, and air are all mixtures

20. salt water Kool Aid Two Types of Mixtures 1. homogeneous: (or solution) particles are microscopic; sample has the same composition and properties throughout; evenly mixed Oh Yeah! e.g., alloy: a homogeneous mixture of metals e.g., bronze (Cu + Sn) pewter (Pb + Sn) brass (Cu + Zn)

21. tossed salad raisin bran paint snowy-bulb gifts Two Types of Mixtures (cont.) 2. heterogeneous: different composition and properties in the same sample; unevenly mixed e.g., suspension: settles over time e.g.,

22. PURE SUBSTANCE MIXTURE ELEMENT COMPOUND HETEROGENEOUS HOMOGENEOUS Chart for Classifying Matter MATTER Has NO chemical formula Has a chemical formula Made of 2 or more different elements Made of 1 element Unevenly mixed Uniform or evenly mixed throughout (a solution)

23. Double Bubble Mind Map Alike Different Different Topic Topic

24. Mixture vs. Compound Alike Different Different Involve substances Variable Composition Fixed Composition Topic Topic No bonds between components Contain two or more elements Bonds between components Mixture Compound Can ONLY be separated by chemical means Can be separated by physical means Can be separated into elements

25. Contrast… 24K GOLD 14K GOLD 14/24 atoms are gold 24/24 atoms are gold mixture of gold & other metals pure gold element homogeneous mixture Au e.g., Au + Cu

26. Compound Composition All samples of a given compound Always have the same composition Every sample of NaCl tastes the same, melts at the same temp., and is 39.3% Na and 60.7% Cl by mass.

27. Phosgene gas (COCl2) is 12.1% carbon, 16.2% oxygen, and 71.7% chlorine by mass. Find # of g of each element in 254 g of COCl2. C: 254 g (0.121) = 30.7 g C O: 254 g (0.162) = 41.1 g O Cl: 254 g (0.717) = 182 g Cl

28. A sample of butane (C4H10) contains 288 g carbon and 60. g hydrogen. Find… A. …total mass of sample = 348 g 288 g C + 60 g H B. …% of each element in butane = 0.828 % C = 82.8% C 17 % H = 0.17 % H = C. …how many g of C and H are in a 24.2 g sample C: 24.2 g (0.828) = 20.0 g C 24.2 g 24.2 g (0.17) H: = 4.2 g H

29. A 550 g sample of chromium (III) oxide (Cr2O3) has 376 g Cr. How many grams of Cr and O are in a 212 g sample of Cr2O3? 68.4% Cr % Cr = and 31.6% O 100 % Cr: 212 g (0.684) = 145 g Cr O: 212 g (0.316) = 67 g O chromium (III) oxide

30. A sample of bronze contains 68 g copper and 7 g tin A. Find total mass of sample = 75 g 68 g Cu + 7 g Sn B. Find % Cu and % Sn and 9.3% Sn 90.7% Cu % Cu = C. How many grams of each element does a 346 g sample of bronze contain? (Bronze is a mixture and isn’t necessarily always 90.7% Cu and 9.3% Sn.) We don’t know! However, assuming these % are correct… Cu: 346 g (0.907) = 314 g Cu (and 32 g Sn)

31. Separating Mixtures …involves physical means, or physical changes 1. sorting: by color, shape, texture, etc. particle size is different 2. filter:

32. filtration in the chemistry laboratory

33. filtration in the “real world”

34. Separating Mixtures (cont.) 3. magnet: one substance must contain iron some substances dissolve more easily than others 4. chromatography:

35. decant: to pour off the liquid blood after high- speed centrifuging Separating Mixtures (cont.) 5. density: “sink vs. float” perhaps use a centrifuge

36. thermometer water out (warmer) water in (cooler) more-volatile substance condenser (i.e., the one with the lower boiling point) mixture more-volatile substance, now condensed heat source Separating Mixtures (cont.) 6. distillation: different boiling points

37. dental amalgam No chemical reactions are needed to separate mixtures; substances are NOT bonded

38. m D V liquids and gases Glass: liquid or solid? Density how tightly packed the particles are Density = Typical units: g/cm3 for solids g/mL for fluids

39. V = ? To find volume, use… 1. a formula V = p ∙ r2 ∙ h V = l ∙ w ∙ h 2. water displacement Vfinal Vinitial Vobject = Vfinal – Vinitial

40. ** Density of water = 1.0 g/mL = 1.0 g/cm3 Things that are “less dense” float in things that are “more dense.” (And things that are “more dense” sink in things that are “less dense.” D < 1 g/cm3 D > 1 g/cm3 D < 1 g/cm3 D < 1 g/cm3 The density of a liquid or solid is nearly constant, no matter what the sample’s temperature Density of gases is highly dependent on temperature

41. Ironwood Trees • Several different varieties of hardwood trees, having densities between 1.34 and 1.49 g/cm3 • Most dense species is South African Ironwood (black ironwood) • Olealaurifolia • Found in Florida and West Indies • D = 1.49 g/cm3

42. m D V Will Bowling Balls sink or float in H2O? If DBB < 1, it will float If DBB > 1, it will sink 21.6 cm in diameter Vsphere = 4/3 p r3 V = 4/3p (10.8 cm)3 V = 5,276.7 cm3 m = D V m = (1.00 g/cm3)(5276.7 cm3) m = 5276.7 g Since the mass of a BB varies, let’s figure out at what mass it will sink v. float …or 11.6 lbs

43. m D V V Density Calculations 1. A sample of lead (Pb) has mass 22.7 g and volume 2.0 cm3. Find sample’s density. = 11 2. Another sample of lead occupies 16.2 cm3 of space. Find sample’s mass. m = D V = 180 g

44. m m D V 1.8 cm 1.5 cm 3. A 119.5 g solid cylinder has radius 1.8 cm and height 1.5 cm. Find sample’s density. V = p r2 h = p (1.8 cm)2(1.5 cm) = 15.268 cm3 = 7.8

45. m m D V 8.2 cm 5.1 cm 4.7 cm 4. A 153 g rectangular solid has edge lengths 8.2 cm, 5.1 cm, and 4.7 cm. Will this object sink in water? (Find the object’s density and compare it to water’s density.) V = l w h = 8.2 cm (5.1 cm)(4.7 cm) cm3 = 196.55 No; it floats. < 1 = 0.78

46. Galilean Thermometer Problem On a cold morning, a teacher walks into a cold classroom and notices that all bulbs in the Galilean thermometer are huddled in a group. Where are the bulbs? At the top of the thermometer, at the bottom or elsewhere? D1 1. Bulbs have essentially fixed masses and volumes. Therefore, each bulb has a relatively fixed density. D2 D3 D4 2. The surrounding liquid has a fixed mass, but its volume is extremely temperature-dependent. D5

47. D1 D2 D3 D4 D5 Vliq Vliq 3. The density of the liquid can be written as… so… …if the liquid is cold: …but if it’s hot: Dliq mliq mliq = = Dliq On a cold morning, where are the bulbs? AT THE TOP

48. Osmium

49. ONE OF THESE AND ONE OF THESE Properties of Matter CHEMICAL properties tell how a substance reacts with other substances PHYSICAL properties can be observed without chemically changing the substance EXTENSIVE properties depend on the amount of substance present INTENSIVE properties do not depend on the amount of substance

50. Examples: P, I electrical conductivity……………………..… C, I reactivity with water………………………..... P, E heat content (total energy)………………..… P, I ductile: can be drawn (pulled) into wire….. malleable: can be hammered into shape… P, I P, I brittle……………………………………………. P, I magnetism………………………………………