Intermolecular Forces, Liquids, And Solids
Slide 1 / 136Slide 2 / 136Intermolecular Forces,Liquids, and SolidsSlide 3 / 136Table of ContentsClick on the topic to go to that section· States of Matter· Intermolecular Forces· Types of Intermolecular Forces· Intermolecular Forces and Physical Properties· Vapor Pressure· Phase Changes and Phase Diagrams· Types of Solids
Slide 4 / 136States of MatterReturn toTable ofContentsMatter We SeeSlide 5 / 136Atoms are the basic units of matter. At the atomic level, weknow atoms bond together to create compounds due toelectronegativity and Coulombic or electrostatic attraction.Chemical compounds react with each other, breaking andre-forming bonds, to make new chemicals.What molecules are formed in the reaction below?Write the chemical equation.Represents Oxygen atomRepresents Hydrogen atom Matter We SeeWe also know that atoms and molecules are very small. We can'tactually see a substance unless it is made up of many particles.1 mL of water at 4 Celsius 1 gram of water1 gram of water 0.056 moles of water0.056 moles of water 3.34x1022 molecules of waterWhat makes all of the water molecules stick together to make alarge enough amount we can actually see?Slide 6 / 136
Slide 7 / 136So far this year .We first explained atoms, elements and how to build up theperiodic table from quantum numbers.Then we explained how atoms combine to form molecules - themost common way we find most atoms in nature - and learnedabout how atoms from molecules rearrange in chemicalreactions to form new chemical compounds.Now, we're going to use intermolecular forces betweenmolecules to create the common states of matter.Slide 8 / 136Intermolecular ForcesIntermolecular forces are the piece we need to add to thepuzzle to explain the world around us.Without intermolecular forces, we wouldn't have tables,lakes, wall.or even our bodies.Intermolecular forces shape our world.States of MatterWhile there are many states of matter, the three common statesthat dominate our world are gases, liquids and solids.We won't be discussing more exotic states such as plasma,nuclear matter, etc.The 2 fundamental differences between states of matter are:the distance between particlesthe particles' freedom to moveSlide 9 / 136
Slide 10 / 136States of MatterGasLiquidcool orincreasepressurecoolheat ordecreasepressureParticles are farapart,total freedom,much of emptyspace,total disorderCrystalline solidheatdisorder, freedom,free to moverelativeto each other,close togetherorderedarrangement,particles are infixedpositions,close togetherSlide 11 / 136SolidLiquidGasEnjoy this musical interlude byThey Might Be Giants!Characteristics of the States of MatterGasSHAPEAssumes the shape ofits containerVOLUMEExpands to the volume ofits containerCOMPRESSIONIs compressibleFLOWFlows easilyDIFFUSIONVery RapidSlide 12 / 136
Characteristics of the States of MatterSlide 13 / 136LiquidAssumes the shape of the part of acontainer it occupiesSHAPEVOLUMEDoes not expand to the volumeof the containerCOMPRESSIONIs virtually incompressibleFLOWFlows easilyWithin a liquid, slowDIFFUSIONCharacteristics of the States of MatterSlide 14 / 136SolidSHAPERetains its own shaperegardless of containerVOLUMEDoes not expand to thevolume of its containerIs virtually incompressibleCOMPRESSIONDoes not flowFLOWWithin a solid,very very slowDIFFUSIONCondensed PhasesIn the solid and liquid states particles are closer together,we refer to those states as condensed phases.Gascool orincreasepressureLiquidcoolheatheat ordecreasepressureParticles are farapart,total freedom,much of emptyspace,total disorderCrystalline Soliddisorder, freedom,free to moverelativeto each other,close togetherorderedarrangement,particles are infixedpositions,close togetherSlide 15 / 136
1 Which of the following is a characteristic of a gas?Slide 16 / 136A Fills only a portion of its containerB Molecules are in relatively rigid positionsC Takes on the shape of its entire containerD Is not compressibleE Diffuses very slowly2 Which of the following is a characteristic of a liquid?Slide 17 / 136A Fills only a portion of its containerB Molecules are in relatively rigid positionsC Takes on the shape of its entire containerD Is compressibleE Diffusion is very rapid within it3 Which of the following is a characteristic of a solid?A Fills all of its containerB Molecules are in relatively rigid positionsC Takes on the shape of its entire containerD Is compressibleE Diffusion is very rapid within itSlide 18 / 136
Slide 19 / 136Intermolecular ForcesReturn toTable ofContentsStates of Matter & Intermolecular ForcesSlide 20 / 136The state of a substance at a particular temperatureand pressure depends on two major factors:The strength of the intermolecular forces that hold moleculestogetherThe kinetic energy of the moleculesMolecules have the highest kinetic energy in which state?Intermolecular ForcesHClCovalent bond(strong)HClIntermolecularattraction ( weak)Intermolecular forces are electrostatic forces of attraction orrepulsion that exists between molecules.The attractions between molecules, intermolecular forces, arenot nearly as strong as the intramolecular attractions that holdcompounds together.Slide 21 / 136
Slide 22 / 1364 A chemical bond isA an electrostatic force of repulsionB an electrostatic force of attractionC a physical connection between objects that aretouchingD none of the above5 Which of the following correctly ranks electrostatic forcesfrom weakest to strongest?Slide 23 / 136A covalent bond, ionic bond, intermolecular forcesB ionic bond, covalent bond, intermolecular forcesC intermolecular forces, covalent bond, ionic bondD intermolecular forces, ionic bond, covalent bond6 Which of the following is pointing to an intermolecularbond?BDACSlide 24 / 136
7 The arrow below is pointing to a(n)Slide 25 / 136A Intramolecular bondB Ionic bondC Intermolecular bondD Both A and BE Both B and CStates of Matter & Intermolecular ForcesSlide 26 / 136Without intermolecular forces (IMF's), all substances wouldbehave like ideal gases.there would be no liquids or solids.Kinetic Energy and TemperatureTemperature is directly proportional to the average kineticenergy of the molecules that make up a substance.clip: Indiana UniversityThe more kinetic energy molecules have, the higher thetemperature.Slide 27 / 136
Intermolecular Forces & Boiling PointsSlide 28 / 136Boiling represents a transition from a liquid to a gas.To make that transition, molecules in the liquid must break freeof the intermolecular forces that bind them.Intermolecular Forces & Boiling PointsSlide 29 / 136The kinetic energy of the molecules is proportional to thetemperature: as kinetic energy rises, so does temperature.The boiling point refers to the temperature at which themolecules' energy overcomes the intermolecular forces bindingthem together.The higher the boiling point of a substance, the stronger theintermolecular forces.Water moleculesovercome theirintermolecular forces at100 C.Slide 30 / 1368 Intermolecular forces are strongest inA solidsB liquidsC gases
9 A substance boils when the kinetic energy of itsmoleculesSlide 31 / 136A overcomes the intermolecular forces bonding themtogetherB overcomes the intramolecular forces bonding themtogetherC reaches 100 CelsiusD none of the aboveSlide 32 / 136Types ofIntermolecular ForcesReturn toTable ofContentsSlide 33 / 136Intermolecular ForcesThere are three types of Intermolecular Forces(also known as van der Waals Forces)that bond molecules together:Dipole-dipole interactionsLondon dispersion forces (LDF's)Hydrogen bonding
Slide 34 / 136Dipole-Dipole InteractionsA dipole is a polar molecule.Remember what makes a molecule polar?Bond TypeElectronegativity Differencevery small or zeroNon-Polar Covalentabout 0.2 to 1.6Polar Covalentabove 1.7(between metal & non-metal)IonicSlide 35 / 136DipolesHF is an example of a polar molecule or dipole. The fluorine end ofthe molecule has higher electron density than the hydrogen end.HFWe use thesymbol to designate a dipole (2 poles).The " " end is on the more positive end of the molecule and thearrow points towards the more negative end.Slide 36 / 136Dipole-Dipole Interactions--The positive end of one is attracted to thenegative end of the other and vice-versa. The interaction betweenany two like charges isrepulsive (black)Molecules that have permanentdipoles are attracted to each other. - Only polar molecules will have this typeof Intermolecular Force.-These forces are only important when themolecules are close to each other.- - The interaction between anytwo opposite charges isattractive ( red)
Slide 37 / 136Dipole-Dipole InteractionsThe polarity of a molecule is measured by its dipole moment, m .The more polar the molecule, the greater its dipole moment.The more polar the molecule, the stronger the attractionbetween molecules, the higher the boiling eAcetonitrile, CH CNAcetaldehyde, CH CHOMethyl chloride, CH ClDimethyl ether, CH OCHPropane, CH CH 355294249248231Slide 38 / 13610 Which of the molecules below will have the highestboiling point?cula rS ubs ta nce MoleWt.B CH3OCH3CH3CH2CH3C CH3ClCH3ClCH3CHOCH3CND CH3CHOCH3OCH3DipoleMome nt44465044410.11.31.92.73.9AnswerA CH3CH2CH3E CH3CNSlide 39 / 13611 Which of the following will have the lowest boilingpoint?B CH3OCH3cula rS ubs ta nce MoleWt.CH3CH2CH3C 1DipoleMome nt0.11.31.92.73.9AnswerA CH3CH2CH3
London Dispersion ForcesSlide 40 / 136London Dispersion Forces occur between all molecules.They result from the fact that electrons are in constant motionand sometimes are the same side of the molecule.When they are on one side, the molecule is polarized: oneside is negative and the other is positive; the molecule actslike a dipole.δ-δ -London Dispersion ForcesSlide 41 / 136That polarization creates an electric field that oppositelypolarizes nearby molecules.leading to an attraction.δ-δ-δ -δ -Slide 42 / 136London Dispersion ForcesWhile the electrons in helium atoms repel each other, theyoccasionally wind up on the same side of an atom.At that instant, the helium atom is polar, with anexcess of electrons on one side and a shortage on the other.ee-2 Helium atomδ-δ
London Dispersion ForcesSlide 43 / 136Another helium atom nearby becomes polarized as the electrons onthe left side of the first atom repel the electrons in the second atom.electrostatic attractione-2 ee-Helium atom 1e-2 Helium atom 2London dispersion forces, or dispersion forces, are attractionsbetween an instantaneous dipole and an induced dipole.δ-δ δ-δ Slide 44 / 136PolarizabilityThese forces are present in all molecules, whether they arepolar or nonpolar.The tendency of an electron cloud to distort in this way iscalled polarizability.Because larger molecules have more electrons, they aremore polarizable. Molecules with more electrons experiencestronger London dispersion forces.London Dispersion ForcesExamine the trends among the Halogens and the Noble Gases:Number BoilingNobleHalogen ofPointgaselectrons (K)F2Cl2Br2I218347010685.1 He238.6 Ne332.0457.6ArKrXeNumberBoilingofpoint (K)electrons2101836544.627.387.5120.9166.1the greater the number of electrons,the more polarizable the particles are,resulting in stronger London dispersion forces.Slide 45 / 136
12 Only polar molecules are bonded together by Londondispersion forces.Slide 46 / 136TrueFalse13 Molecules with more electrons experience strongerLondon dispersion forces.Slide 47 / 136TrueFalse14 Which of the following molecules will have the highestboiling point?A F2B Cl2C Br2D I2Slide 48 / 136
15 Which of the following molecules will have the lowestboiling point?Slide 49 / 136A F2B Cl2C Br2D I216 Which of the following gases will have the highest boilingpoint?Slide 50 / 136A HeB NeC ArD KrE Xe17 Which of the following gases will have the lowest boilingpoint?A HeB NeC ArD KrE XeSlide 51 / 136
Slide 52 / 136Which Have a Greater Effect?Dipole-Dipole Interactions or Lond Dispersion ForcesDipole-DipoleLondon Dispersion ForcesIf two polar moleculesare of comparablesize, dipole-dipoleinteractions are thedominating force.If one molecule is muchlarger than another,dispersion forces will likelydetermine its physicalproperties.If molecules are nonpolar,dispersion forces willdominate, since all moleculesexperience dispersion forces.Slide 53 / 136Hydrogen BondingThe graph shows the boilingpoints for four polar and fournon-polar compounds.For the non-polar series (CH4to SnH4) boiling pointsincrease with higher numberof electrons.There are stronger dispersionforces due to greaterpolarizability.Hydrogen BondingExamine the boiling points for thefour polar compounds (4,2,2 bent) called Group 16 hydrides.First look at the trend from H2 S toH2 Te. The boiling points arehigher than the non-polar series,and the boiling points increasewith greater molecular weight/greater numbers of electrons asexpected.What is going on with water?Based on molecular weight/electron number, it should have thelowest boiling point among the polar compounds, but instead itsboiling point is extremely high.Slide 54 / 136
Hydrogen BondingSlide 55 / 136The dipole-dipole interactionsexperienced when H is bonded toN, O, or F are unusually strong.We call these interactionshydrogen bonds.Hydrogen BondingSlide 56 / 136Hydrogen bonding arises in part from the high electronegativityand small radius of nitrogen, oxygen, and fluorine.When hydrogen is bonded to one of those very electronegativeelements, the hydrogen nucleus is exposed.FFClick here to watch an animation about Hydrogen BondingHydrogen BondingWater is the only substance that is lessdense in the solid state than in the liquidstate; therefore, solid water, or ice, floatson liquid water.If it didn't, life on Earth would bevery different. For instance,lakes would freeze from thebottom and fish couldn't survive winters.Hydrogen bonding creates thespace in ice that explains its low density.Click here to watch an animationof the Water - Ice transitionSlide 57 / 136
18 Which of the following molecules has hydrogen bondingas one of its intermolecular forces?Slide 58 / 136A HFB HClC HBrD HIE All of the above19 Which of the following molecules has hydrogen bondingas one of its IMF's?Slide 59 / 136A CH3FB CH3ClC HBrD NO2E None of the aboveSlide 60 / 136Ion-Dipole InteractionsThere is a fourth intermolecular force between ions andmolecules that will be important as we explore solutionslater this year. Ion-dipole interactions are not considered avan der Waals force.- The ion-dipole forces cause ionic substances to dissolvein polar solvents. --- - - --Anion-dipole attractionsCation-dipole attractions
Summary ofInteractionsNoAre ions involved?Are polar moleculesinvolved?Are polar moleculesand ions bothpresent?YesNoSlide 61 / 136YesYesNoIon-dipoleforces:NaCl in H2O*IonicBonding:NaCl, KIAre hydrogenatoms bondedto N, O, or Fatoms?YesNoDispersion Dipole-dipoleforces only: forces: H2S,Ar, I2CH3, ClHydrogenbonding:H2O, NH3Van der Waals ForcesClick here to watch a summary of IMFSlide 62 / 136IMF SummaryLondonDispersionForcesStrengthTypes ofmoleculesWhen indoubt.Weakest IMFAll nonpolarmolecules;All moleculesLook atnumber ofelectronsDipole-DipoleHydrogenBondingStronger IMFStrongest IMFOnly polarmoleculesOnly polarmolecules withH bonded toN, O, or FLook at givenDipolemomentLook for H-N,H-O, or H-Fbonds20 Which of the following has London dispersion forces asits only IMF?A PH3B H2SC HClD SiH4E None of the aboveSlide 63 / 136
21 How many of these substances would have dipole-dipoleinteractions?H 2OCO2CH4Slide 64 / 136NH3A 0B 1C 3D 3E 422 Which of the following molecules will have the highestboiling point?Slide 65 / 136A H2OB CO2C CH4D NH323 Which of the following diatomic molecules has thehighest boiling point?A N2B Br2C H2D Cl2E O2Slide 66 / 136
24 Of the following diatomic molecules, which as the lowestboiling point?Slide 67 / 136A N2B Br2C H2DCl2EO225 Which one of the following derivatives of methane (CH4)has the lowest boiling point?Slide 68 / 136A CBr4B CF4C CCl4D CI4Slide 69 / 13626 Which one of the following derivatives ofmethane (CH4 ) has the highest boiling point?A CBr4B CF4C CCl4D CI4
Slide 70 / 136IMF's and PhysicalPropertiesReturn toTable ofContentsIntermolecular Forces Affect ManyPhysical PropertiesSlide 71 / 136The strength of the attractionsbetween particles can greatlyaffect the properties of asubstance or solution.Slide 72 / 136Properties of Liquids: ViscosityResistance of a liquid to flow is calledviscosity.It is related to the ease with which moleculescan move past each other. Viscosity increaseswith stronger intermolecular forces anddecreases with higher temperature.Which liquid to the right is more Viscosity ( 23.26 x 104.09 x 105.42 x 107.11 x 101.42 x 10-43CHCH CHCH CH CHCH CH CH CH-4323223222-4-43-3
Properties of Liquids:Surface TensionSlide 73 / 136Surface tension results from the net inward forceexperienced by the molecules on the surface of a liquid.Properties of Liquids:Surface TensionSlide 74 / 136The surface tension of a liquid is directly related to the attractiveforces between its molecules. The stronger the attractive forcesthe more surface tension is needed to increase the surface area ofthe liquid.Water has a relatively high surface tension 7.29 x 10-2 J/m2 at 20 .However, mercury has an even higher surface tension: 4.6 x 10 -1J/m2.What do you think could cause mercury to have such a highsurface tension relative to water?27 A substance's viscosity is directly proportional to thestrength of its intermolecular forces?TrueFalseSlide 75 / 136
28 Which of the following substances would have thegreatest viscosity?Slide 76 / 136A CH3CH2CH2CH2CH2CH3B CH3CH2CH2CH3C CH3CH2CH2CH2CH2CH2CH2CH3D CH3CH2CH2CH3Slide 77 / 13629 The unbalanced attraction of molecules at the surface ofa liquid tends to pull the bulk of the moleculesleaving a minimal number on the surface.A outwardB inwardC in all directionsSlide 78 / 136Vapor PressureReturn toTable ofContents
VaporizationSlide 79 / 136Boiling and evaporation are two ways in which a liquid canvaporize into a gas. However, there are importantdistinctions between these processes.BoilingEvaporationOccurs at a specifictemperature, the boilingpoint (B.P.)Occurs below the boilingpointOccurs throughout theentire liquidOccurs only at the surface ofa liquidAchieved when atmosphericpressure equals vaporpressure (Patm Pvap)Vapor PressureSlide 80 / 136Vapor pressure is the pressure exerted by gasmolecules above the surface of an enclosed liquid.Sample (A) at a lowertemperature shows somevapor above the surface ofthe liquid.Sample (B) at a highertemperature shows a greaternumber of vapor particles, thusresulting in higher vaporpressure.Properties of Liquids: VolatilityVolatility is another characteristic of a liquid that is basedupon the strength of its intermolecular forces.The more volatile a liquid:the more quickly it evaporatesthe higher its vapor pressure at a given temperaturethe weaker its intermolecular forcesAcetone is used to quickly dry glassware in a chemistry lab?Why?Click here to see ashort video on volatilitySlide 81 / 136
Slide 82 / 136Vapor PressureAt any temperature some molecules in a liquid haveenough energy to escape.As the temperature rises, the fraction of molecules thathave enough energy to escape increases.Liquid - Vapor EquilibriumliquidbecomesgasgasbecomesliquidSlide 83 / 136As more molecules escapethe liquid, the pressurethey exert increases.P FAEventually, the liquid andvapor reach a state ofdynamic equilibrium: liquidmolecules evaporate andvapor molecules condenseat the same rate.Slide 84 / 136Vapor Pressure CurveLike any line, the curve is madeup of an infinite number ofpoints.Each point along the curveshows the temperature atwhich atmospheric pressureequals vapor pressurePatm PvapIn other words, each pointalong the curve indicates aboiling point.The type of graph shown here is called avapor pressure curve.
Vapor Pressure CurveSlide 85 / 136The boiling point of a liquid isthe temperature at which itsvapor pressure equalsatmospheric pressure.The normal boiling point isthe temperature at which itsvapor pressure is 760 torr.(AKA 760 mm Hg 1 atm)30 What is the normal boiling point of ethanol?Slide 86 / 136A 34.6B 40.0C 60.0D 78.3E 100.0Slide 87 / 13631 What is the boiling point ( in o C) of diethyl ether at200 torr?A -10B 0C 760D 35
32 What is the boiling point of water at 300 torr?Slide 88 / 136A 50B 75C 90D100E200Pressure CookingSlide 89 / 136A liquid will boil when itsvapor pressure equalsatmospheric pressure.A pressure cooker works byincreasing the"atmospheric"pressure inside it, so waterwill not boil at 100 ;instead, it may be heatedRaising the cooking temperature cuts cooking time drastically.up to 120 before turningto steam.Pressure Cookingwww.washingtonpost.comSlide 90 / 136
Slide 91 / 136Boiling Point and PressureRecall that boiling occurs whenPvap PatmSince atmospheric pressure is solow at high altitudes, (e.g. top ofMount Everest) water will boil at amuch lower temperature than inNew Jersey.Click here for a video ofwater boiling atroom temperaturePatm 33 kPa on Mt. EverestPatm 101.3 kPa at sea level33 It will take longer to hard-boil an egg (cooking timeonly)Slide 92 / 136A At the summit of Mt. EverestB At sea levelC Cooking times are equal at both elevationsSlide 93 / 136Phase DiagramsReturn toTable ofContents
Phase ChangesSlide 94 / 136A phase change is a physical rearrangement of molecules.Substances can change states or phases as a result ofchange in external conditions like pressure and temperature.Phase ChangesSlide 95 / 136The temperature and pressure at which a substance willchange phases depends on the intermolecular forces holdingthe substance together.At STP, CO2 sublimates atAt STP, H2O boils at-78.5 Celsius100 CelsiusEnergy Changes Associated withChanges of StateChemical and physical changes are usually accompanied bychanges in energy.When energy is released in the form of heat, the process isexothermic.Examples: making ice cubes, formation of snow in clouds,condensation of rain water, a candle flameWhen energy is absorbed by the system, the process isendothermic.Examples: melting ice cubes, conversion of frost to water vapor,evaporation of water, baking bread, cooking an egg, melting solidsalts.Slide 96 / 136
Exothermic sitionCoSlide 97 / idSolidEndothermic sitionCoSlide 98 / idSolid* 34What is the VSEPR number of the only substance wecommonly see in all 3 states of matter?A 220B 422C 431D I don't remember how to do thisSlide 99 / 136
35 Which of the following is not a phasechange?Slide 100 / 136A VaporizationB EffusionC MeltingD Sublimation36 The change of a substance from a solid to a gas iscalled?Slide 101 / 136A VaporizationB EffusionC MeltingD Sublimation37 Which of the following is an endothermic process?A CondensationB DepositionC MeltingD FreezingSlide 102 / 136
Phase DiagramsSlide 103 / 136A phase diagram indicates what state a substance is in ata given temperature and pressure.Critical pointsolidPressureliquidVaporTriple pointTemperaturePhase DiagramsSlide 104 / 136The triple point represents the pressure and temperature atwhich all three states are in equilibrium. The critical pointrepresents the pressure and temperature at which liquid andvapor phases become indistinguishable.Critical pointsolidPressureliquidVaporTriple pointTemperaturePhase DiagramsThis line represents the interface between solid and liquid.The melting point at a particular temperature and pressurecan be found along this line.Critical pointsolidPressureliquidVaporTriple pointTemperatureSlide 105 / 136
Phase DiagramsSlide 106 / 136Below the triple point, a substance cannot exist in liquid state.This line represents the interface between solid and vapor.Sublimation points can be found along this line.Critical pointsolidPressureliquidVaporTriple pointTemperaturePhase DiagramsSlide 107 / 136The line between the triple point and the critical point represents theinterface between liquid and vapor. Evaporation points can be foundalong this line.Critical pointsolidPressureliquidVaporTriple pointTemperaturePhase Diagram of WaterNote the highcritical temperatureand criticalpressure.These are due tothe strong van derWaals forcesbetween watermolecules.Slide 108 / 136
Comparison of Two Phase DiagramsFor water, the slope of thesolid-liquid line is negative.This means that an increase inpressure can cause thissubstance to melt. Water is theonly substance that does this.Slide 109 / 136For carbon dioxide, theslope of the solid-liquid lineis positive, as it is for mostother substances. Thismeansthat an increase in pressure cancause substances to freeze.Phase Diagram of Carbon DioxideSlide 110 / 136Carbon dioxide cannot exist inthe liquid state at pressuresbelow 5.11 atm;CO2 sublimes at normalpressures.Click here to see video of "dry ice"38 For a given substance, the temperature and pressure atwhich liquid and gas phases are indistinguishable iscalledA The vapor pointB The triple pointC The critical pointD The danger zoneSlide 111 / 136
39 The temperature and pressure at which a substance cansimultaneously melt, evaporate, and sublime is calledSlide 112 / 136A The vapor pointB The triple pointC The critical pointD The danger zone40 At which temperature and pressure can the substancebelow simultaneously melt, sublime, and evaporate?Slide 113 / 136A -10 C, 1 atmB 140 C, 1 atmC 10 C, 0.5 atmD -110 C, 0.4 atmPhase Diagram for Imaginary Substance41 For the substance below, X represents which phase?A solidB liquidC vaporD plasmaYXZPhase Diagram for Imaginary SubstanceSlide 114 / 136
42 For the substance below, Y represents which phase?Slide 115 / 136A solidYB liquidXC vaporZD plasmaPhase Diagram for Imaginary Substance43 At standard atmospheric pressure (1 atm), at whattemperature will the substance below melt?Slide 116 / 136A -20 CYB -15 CC -10 CXZD 0CPhase Diagram for Imaginary Substance44 For the substance below, Z represents which phase?A solidB liquidC vaporD plasmaYXZPhase Diagram for Imaginary SubstanceSlide 117 / 136
Slide 118 / 13645 At 0.5 atm and -15 C the substance willA remain solidB meltYXC sublimeZD super coolPhase Diagram for Imaginary Substance46 Which line segment indicates this is definitely a phasediagram for water? Why?Slide 119 / 136A AB B-FC C-BD D-FE E-BSlide 120 / 136Types of SolidsReturn toTable ofContents
Slide 121 / 136SolidsWe can think of solids as falling into two groups.Crystalline, in whichparticles are in highlyordered arrangement.Amorphous, in which there isno particular order in thearrangement of particles.NDT Educa tion Re s ource Ce nte rSlide 122 / 136Amorphous SolidsSome examples of amorphous solids are: rubber, glass,paraffin wax and cotton candy.Crystalline solids include ionic compounds, metals and anothergroup called covalent-network solids. Crystalline solids arecategorized by bonding type as shown on the next slide.Types of Bonding in Crystalline SolidsType ofSolidForm ofUnitParticlesMolecularAtoms dipolehydrogenbondsHard and brittle, lowmelting point, poorthermal and electricalconductionCovalentbondsFairly soft, low tomoderately high meltingpoint, poor thermal andelectrical conductionPositive andnegative ionsCoulombicattractionsAtomsMetallicbondsVery hard, very highmelting point,variable thermal andelectrical conductionSoft to very hard, low tovery high melting point,excellent thermal andelectrical conduction,malleable and ductileExamplesAr, CH4,CO2,C6H12O6Diamond (C),Quartz (SO2)Typical saltsAll MetallicElements:Cu, Fe, Al,etc.Slide 123 / 136
Covalent-Network Solids: DiamondSlide 124 / 136Diamonds are an exampleof a covalent-network solid,in which carbon atoms arecovalently bonded to fourother carbon atoms.They tend to be hard andhave high melting points.Covalent-Network Solids: GraphiteSlide 125 / 136Graphite is another exampleof a covalent-network solid.Each carbon atom iscovalently bonded to 3 othersin layers of interconnectedhexagonal rings.The layers are held togetherby weak dispersion forces.The layers slide easily acrossone another, so graphite isused as a lubricant as well asthe "lead" in pencils.Slide 126 / 136Metallic SolidsMetals are not covalentlybonded, but the attractionsbetween atoms are too strongto be van der Waals forces.In metals, valence electronsare delocalized throughout thesolid. This means that the"sea" of electrons movesfreely around all the nuclei.MeMeclick here for an animation aboutmetallic bondingMeeMeMee-eMee-MeMee-Mee-Meee-MeMe
Properties of Metallic SolidsSlide 127 / 136The delocalized nature of theelectrons in metals accounts formany physical properties.For example, metals are generally:good conductors of heat andelectricity malleable and ductile, (i.e.may be drawn into wires)Glass MakingSlide 128 / 136Glass is made by melting a mixture of sand and otherminerals in a furnace at 1800 C.Lightning can also fuse sand into silica glass at 1800 C.Fulgurite via theMine ra logica l Re s e a rch Compa nyClick here to see a video ofhow glass is made from sand47 What type of solid is depicted in image below?A crystalline solidB amorphous solidC metallic solidD covalent-network solidE Impossible to determineSlide 129 / 136
48 What type of solid is depicted in imagebelow?Slide 130 / 136A ionic solidB amorphous solidC metallic sol
Molecules have the highest kinetic energy in which state? Slide 20 / 136 Intermolecular Forces Intermolecular forces are electrostatic forces of attraction or repulsion that exists between molecules. The attractions between molecules, intermolecular forces, are not nearly as strong as the intramolecular
AP Chemistry Chapter 11. Intermolecular Forces, Liquids, and Solids - 1 - Chapter 11. Intermolecular Forces, Liquids, and Solids 11.2 Intermolecular Forces Intermolecular forces are much weaker than ionic or covalent bonds (e.g., 16 kJ/mol versus 431 kJ/mol for HCl). Melting o
AP Chemistry: Intermolecular Forces, Liquids, and Solids Lecture Outline 11.1 A Molecular Comparison of Liquids and Solids Physical properties of liquids and solids are due to intermolecular forces. These are forces between molecules. Physical properties of substa
Intermolecular Forces 11.2 Intermolecular forces are attractive forces between molecules. Intramolecular forces hold atoms together in a molecule. Intermolecular vs Intramolecular 41 kJ to vaporize 1 mole of water (inter) 930 kJ to break all O-H bonds in 1 mole of water (intra) Generally,
Real Gases: Deviations from Ideal Behavior 184 11 LIquIDs AnD InTerMoLeCuLAr ForCes 193 A Molecular Comparison of Gases, Liquids, and Solids 193 Intermolecular Forces 196 Select Properties of Liquids 200 Phase Changes 201 Vapor Pressure 202 12 soLIDs AnD MoDern MATerIALs 211 Classification of Solids 211 Metallic Bonding 213 Ionic Solids 215
Mar 06, 2007 · intermolecular forces. Volatility-The more volatile, the weaker the intermolecular forces. Vapor pressure-The higher the vapor pressure, the weaker the intermolecular forces. The melting point/boiling point is higher in substances that have stronger intermolecular forces. Other physical properties include viscosity.File Size: 556KB
Intermolecular Forces 1. Evidence for Intermolecular Forces 2. Phase Diagrams (briefly) 3. Liquid-Vapor Equilibrium 1. Kinetic theory 2. Gas escape as a way to measure liquid intermolecular forces 4. Boiling points related liquid Intermolecular Forces 1. Dipole-dipole 2. Dispersion 3. H-b
LIQUIDS, SOLIDS, AND INTERMOLECULAR FORCES PRACTICE EXAMPLES 1A (E) The substance with the highest boiling point will have the strongest intermolecular forces. The weakest of van der Waals forces are London forces, which depend on molar mass (and surface area): C3H8 is 44 g/mol,
DEPARTMENT OF BOTANY Telangana University Dichpally, Nizamabad -503322 (A State University Established under the Act No. 28 of 2006, A.P. Recognized by UGC under 2(f) and 12 (B) of UGC Act 1956)
