Intermolecular Forces And Liquids And Solids

Intermolecular ForcesandLiquids and SolidsChapter 11Based on ppt from Mr.Rapp’s AP chemistrywebsite and modifiedfor our needshttp://www.chemistrygeek.com/chem2.htm

A phase is ahomogeneous part ofthe system in contactwith other parts of thesystem but separatedfrom them by a welldefined boundary.

Resources and Activities Textbook - chapter 11 & ppt file Online practice quiz from Pearson- chapter 11 Lab activitiesIntermolecular Forces, Liquidsand Solids(Chapter 11)Chemtour videos from W.W.Norton chapter 10 :intermolecular forces; phasediagrams; (capillary action)– Molar mass of a volatile liquid POGIL activities:– Phase changes– Intermolecular Interactions– Vapor Pressure Curves Comprehensive tutorial andanimations on Intermolecular gilbert2/contents/ch10/studyplan.aspChapter 11 Animations fromglencoe website for 0023654666/studentview0/chapter11/animations center.html

Activities and Problem set for chapter 11(due date )TextBook ch. 11 - required for regents (inpart), SAT II and AP exams Do chapter 11 GIST (p. 445, 446, 447,448, 452, 454, 456, 461, 463) andVisualizing concepts problems 11.1-11.6Lab activities: (determining molar massof volatile liquids)(6 total) - write out questions and answersPOGILS (3)questions is also acceptable)–––Phase changesIntermolecular InteractionsVapor Pressure Curves& show work. (NB Photocopy of Do End of chapter exercises:11.9, .11,.13, .15, .17, .19, .21, .23, .25, .27, .29,.33, .35, .37, .39, .41, .43, .45, .47, .49,Online practice quiz ch 11 due by.51, .53, .55, .71, .73, .75, .85, .100

Animation on intermolecular forces, liquids, and solids to view in class and at bert2/contents/ch10/studyplan.asp(Intermolecular forces)Animations on vapor pressure and unit cells to view in class and at home:In class preview and then Independent work - students to view animations &interactive activities (4 in total – 1 from Norton and 3 from the Glencoe site forChang’s book) and write summary notes on each. These summaries are to beincluded in your 54666/student view0/chapter11/animations center.html

Intermolecular ForcesIntermolecular 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,intermolecularforces are muchweaker thanintramolecularforces.“Measure” of intermolecular forceboiling pointmelting pointDHvapDHfusDHsub11.2

Molecular Interaction Flowchart

Types of Intermolecular Forces1. Hydrogen Bond (strongest)The hydrogen bond is a special dipole-dipole interactionbetween the hydrogen atom in a polar N-H, O-H, or F-H bondand an electronegative O, N, or F atom. IT IS NOT A BOND.AH BorAH AA & B are N, O, or F11.2

Water is a Unique SubstanceMaximum Density40CDensity of WaterIce is less dense than water11.3

Why is the hydrogen bond considered a“special” dipole-dipole interaction?Decreasing molar massDecreasing boiling point11.2

Types of Intermolecular Forces2. Ion-Dipole ForcesAttractive forces between an ion and a polar molecule. Themagnitude of the attraction increases as either the charge of the ionor the magnitude of the dipole increases.Ion-Dipole Interaction11.2

Types of Intermolecular Forces3. Dipole-Dipole ForcesAttractive forces between polar moleculesOrientation of Polar Molecules in a Solid11.2

Types of Intermolecular Forces4. Dispersion Forces – van der Walls forces/London forces(weakest)Attractive forces that arise as a result of temporarydipoles induced in atoms or moleculesion-induced dipole interactiondipole-induced dipole interaction11.2

Intermolecular Forces4. Dispersion Forces Continued (see Animation)Polarizability is the ease with which the electron distributionin the atom or molecule can be distorted.Polarizability increases with: greater number of electrons more diffuse electron cloudDispersionforces usuallyincrease withmolar mass.11.2

What type(s) of intermolecular forces exist betweeneach of the following molecules?HBrHBr is a polar molecule: dipole-dipole forces. There arealso dispersion forces between HBr molecules.CH4CH4 is nonpolar: dispersion forces.SSO2SO2 is a polar molecule: dipole-dipole forces. There arealso dispersion forces between SO2 molecules.11.2

Intermolecular ForcesIntermolecular 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,intermolecularforces are muchweaker thanintramolecularforces.“Measure” of intermolecular forceboiling pointmelting pointDHvapDHfusDHsub11.2

Properties of LiquidsCohesion is the intermolecular attraction between like moleculesAdhesion is an attraction between unlike moleculesAdhesionattracted to glassCohesionattracted to each other11.3

Properties of LiquidsSurface tension is the amountof energy required to stretch orincrease the surface of a liquidby a unit area. It results fromthe net inward forceexperienced by the moleculeson the surface of a n

Vapor pressure of waterversus temperatureAtmospheric pressure atvarious altitudes

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Molar heat of sublimation(DHsub) is the energy requiredto sublime 1 mole of a solid.DepositionH2O (g)SublimationH2O (s)DHsub DHfus DHvap( Hess’s Law)11.8

Molar heat of fusion (DHfus) is the energy required to melt1 mole of a solid substance.11.8

The boiling point is the temperature at which the(equilibrium) vapor pressure of a liquid is equal to theexternal pressure.The normal boiling point is the temperature at which a liquidboils when the external pressure is 1 atm.11.8

The equilibrium vapor pressure is the vapor pressuremeasured when a dynamic equilibrium exists betweencondensation and evaporationH2O (l)H2O (g)Dynamic EquilibriumRate ofcondensation Rate ofevaporationGo To:http://glencoe.com/sites/common assets/advanced placement/chemistry chang10e/animations/vapor pressure.swf11.8

Molar heat of vaporization (DHvap) is the energy required tovaporize 1 mole of a liquid.Clausius-Clapeyron Equationln P -DHvapRTC constant (depends on P & T)P (equilibrium) vapor pressure CIs this equation on your APreference tables?T temperature (K)R gas constant (8.314 J/K mol)11.8

Where’s Waldo?Can you find The Triple Point?Critical pressure?Criticaltemperature?Where fusionoccurs?Where vaporizationoccurs?Melting point(at 1 atm)?Carbon DioxideBoiling point(at 6 atm)?

An amorphous solid does not possess a well-definedarrangement and long-range molecular order.A glass is an optically transparent fusion product of inorganicmaterials that has cooled to a rigid state without crystallizingCrystallinequartz (SiO2)Non-crystallinequartz glass11.7

A crystalline solid possesses rigid and long-range order. In acrystalline solid, atoms, molecules or ions occupy specific(predictable) positions.An amorphous solid does not possess a well-definedarrangement and long-range molecular order.A unit cell is the basic repeating structural unit of a crystallinesolid.At lattice points:latticepointUnit CellUnit cells in 3 dimensions Atoms Molecules Ions11.4

Go to Glencoe animations chapter 11part I and II packing spheres (units 66/student view0/chapter11/animations center.html

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Types of CrystalsIonic Crystals – Ion-Ion interactions are the strongest(including the “intermolecular forces” (H bonding, etc.) Lattice points occupied by cations and anions Held together by electrostatic attraction Hard, brittle, high melting point Poor conductor of heat and electricityCsClZnSCaF211.6

Types of CrystalsMolecular Crystals Lattice points occupied by molecules Held together by intermolecular forces Soft, low melting point Poor conductor of heat and electricity11.6

Types of CrystalsCovalent Crystals – Stronger than IM forces but generallyweaker than ion-ion Lattice points occupied by atomsHeld together by covalent bondsHard, high melting pointPoor conductor of heat and electricitycarbonatomsdiamondgraphite11.6

Types of CrystalsMetallic Crystals – Typically weaker than covalent, but can bein the low end of covalent Lattice points occupied by metal atomsHeld together by metallic bondsSoft to hard, low to high melting pointGood conductors of heat and electricityCross Section of a Metallic Crystalnucleus &inner shell emobile “sea”of e-11.6

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,