CHAPTER 13 Intermolecular Forces, Liquids and solids

Kinetic Molecular Theory of Matter

Intermolecular Forces

Real gases: van der Waals Equation of State

Empirical correction factors

Ion-Dipole Interactions

Shape and Polarity

Permanent Dipole Moments

Measuring Dipole Moments

Dipole - Dipole interactions Non-polarPolar M (g/mol) bp (  C) M (g/mol) bp (  C) N2N CO SiH PH GeH AsH Br ICl16297 attractive repulsive

Boiling Points in Hydrogen compounds ?

N7N7 O8O8 F9F9 P 15 S 16 Cl 17 As 33 Se 34 Br 35 The Hydrogen Bond A Exceptionally strong DP-DP Force ++ 

H bonding: examples Double H-bonds in acetic acidBoiling points of two isomers: EtOH and DME 78.3  C  C

H Bonding in Water

H bonding and the Structure of DNA

DP – non-DP Forces (dispersion forces)

DP – non-DP and non DP – non DP forces (dispersion forces)

Example of DP – non-DP and non DP – non DP Forces (dispersion forces)

Summary of Intermolecular Forces Increase with A.M H Bonding Increasing Polarity

Energy required for a molecule to leave the liquid phase. Properties of Liquids

Equilibrium Vapour Pressure

Vapour Pressure Curves

The Molar Enthalpy of Vaporization

Example – Vapor Pressure

Critical Temperature and Pressure H2OH2O Triple point

Critical Temperature Data

Importance to common trade gases

Surface tension, viscosity and capillary action

EXERCISE

Solids and Phase Diagrams

Amorphous Solids

Crystalline Solids

X-ray Diffraction

Crystalline solids: Metals

EXERCISE

Sodium Chloride (Rock Salt) Structure Type ohis is based on the face-centred cubic unit cell, insofar as the (large) Cl – ions occupy all the sites of the fcc lattice Ionic Crystals

Physical Properties of Solids

Semicrystalline Materials

Example: Polyvinylidenedifluoride

Electrical Properties of Semicrystalline Materials

Phase Diagrams: H 2 O

Phase Diagrams: CO 2

Important Concepts from Chapter 13 Kinetic-molecular theory of matter Intermolecular forces (four categories, hydrogen bonding) Properties of liquids Vapour pressure Boiling vs. evaporation Enthalpy of vaporization - Clausius-Clapeyron equation Surface tension, capillary action & viscosity Properties of solids Six different types of solids Enthalpy of fusion Enthalpy of sublimation Phase diagrams Predicting changes of state under different conditions Critical point & supercritical fluids Triple point