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I. Intermolecular Forces (Ch. 6, p )

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Presentation on theme: "I. Intermolecular Forces (Ch. 6, p )"— Presentation transcript:

1 I. Intermolecular Forces (Ch. 6, p.189-193)
Ch Liquids & Solids I. Intermolecular Forces (Ch. 6, p )

2 A. Definition of IMF Attractive forces between molecules.
Much weaker than chemical bonds within molecules.

3 B. Types of IMF

4 B. Types of IMF London Dispersion Forces View animation online.

5 B. Types of IMF Attractive forces that arise as a result of temporary dipoles induced in atoms or molecules ion-induced dipole interaction dipole-induced dipole interaction 11.2

6 B. Types of IMF Dipole-Dipole Forces + - View animation online.

7 B. Types of IMF Hydrogen Bonding

8 C. Determining IMF NCl3 polar = dispersion, dipole-dipole CH4
nonpolar = dispersion HF H-F bond = dispersion, dipole-dipole, hydrogen bonding

9 II. Physical Properties (p. 363 - 371)
Ch Liquids & Solids II. Physical Properties (p )

10 A. Liquids vs. Solids IMF Strength Fluid Density Compressible
Diffusion LIQUIDS Stronger than in gases Y high N slower than in gases SOLIDS Very strong N high extremely slow

11 A. Liquids vs. Solids A phase is a homogeneous part of the system in contact with other parts of the system but separated from them by a well-defined boundary.

12 B. Liquid Properties Surface Tension
attractive force between particles in a liquid that minimizes surface area

13 B. Liquid Properties Capillary Action
attractive force between the surface of a liquid and the surface of a solid water mercury

14 B. Liquid Properties Adhesion Cohesion

15 Water is a Unique Substance
Maximum Density 40C Density of Water Water is a Unique Substance 11.3

16 C. Types of Solids Crystalline - repeating geometric pattern
covalent network metallic ionic covalent molecular Amorphous - no geometric pattern decreasing m.p.

17 C. Types of Solids Ionic (NaCl) Metallic

18 C. Types of Solids Covalent Molecular Covalent Network Amorphous (H2O)
(SiO2 - quartz) Amorphous (SiO2 - glass)

19 C. Types of Solids Diamond Graphite

20 C. Types of Solids

21 III. Changes of State (p. 372 - 382)
Ch Liquids & Solids III. Changes of State (p )

22 A. Phase Changes

23 A. Phase Changes Evaporation
molecules at the surface gain enough energy to overcome IMF Volatility measure of evaporation rate depends on temp & IMF

24 Greatest Order Least T2 > T1 Evaporation Condensation

25 A. Phase Changes temp volatility IMF volatility Boltzmann Distribution
# of Particles volatility IMF volatility Kinetic Energy

26 A. Phase Changes Equilibrium
trapped molecules reach a balance between evaporation & condensation

27 A. Phase Changes Vapor Pressure
pressure of vapor above a liquid at equilibrium depends on temp & IMF directly related to volatility

28 A. Phase Changes IMF v.p. v.p. temp

29 A. Phase Changes Patm b.p. IMF b.p. Boiling Point
temp at which v.p. of liquid equals external pressure depends on Patm & IMF Normal B.P. - b.p. at 1 atm Patm b.p. IMF b.p.

30 A. Phase Changes IMF m.p. Melting Point equal to freezing point
Which has a higher m.p.? polar or nonpolar? covalent or ionic? polar ionic

31 A. Phase Changes Sublimation solid  gas
v.p. of solid equals external pressure EX: dry ice, mothballs, solid air fresheners

32 B. Heating Curves Gas - KE  Boiling - PE  Liquid - KE 
Melting - PE  Solid - KE 

33 B. Heating Curves Heat of Vaporization (Hvap)
energy required to boil 1 gram of a substance at its b.p. usually larger than Hfus…why? EX: sweating, steam burns, the drinking bird

34 B. Heating Curves Temperature Change change in KE (molecular motion)
depends on heat capacity Heat Capacity energy required to raise the temp of 1 gram of a substance by 1°C

35 B. Heating Curves Phase Change change in PE (molecular arrangement)
temp remains constant Heat of Fusion (Hfus) energy required to melt 1 gram of a substance at its m.p.

36 C. Phase Diagrams Show the phases of a substance at different temps and pressures.

37 C. Phase Diagrams

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