Week 11 - GeneralChemistry CHEM151 Week 11 UA GenChem...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
UA GenChem General Chemistry General Chemistry CHEM 151 CHEM 151 Week 11
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Forces and Particles INTRAMOLECULAR – forces WITHIN the molecule (particle) which hold atoms together , determine the electron and molecular geometries. N≡N has strong intramolecular forces INTERMOLECULAR – forces BETWEEN separate molecules (particles) – the forces between many particles determine the macroscopic properties .
Background image of page 2
UA GenChem Intermolecular Forces Molecules in a substance interact with each other via  intermolecular forces.  The strength of these forces depends  on the  nature of the atoms  in the  molecule and on the  molecular geometry .
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Intermolecular   forces  determine  properties  of molecular compounds such as:  boiling point, melting point, vapor pressure,  heat of evaporation, heat capacity, etc. Intermolecular Forces
Background image of page 4
UA GenChem Intermolecular Forces In general,  the stronger the  intermolecular  forces, the  higher  the melting point and boiling  point , and the  more energy  will  be required to separate the  molecules  Temperature ( o C) -100 -50 0 50 Gas Gas Liquid Liquid Solid Solid Stronger  Intermolecular Forces What do you think is the effect on  heats of fusion and vaporization?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Dipole-Dipole Forces The intermolecular forces between molecules with  permanent dipole moments  are called  dipole-dipole forces. O O O - δ + δ C C + δ - δ - δ + δ C The energy needed to separate  The energy needed to separate  two polar molecules ranges from  two polar molecules ranges from  5 to 25 kJ/mol 5 to 25 kJ/mol
Background image of page 6
UA GenChem Dipole-Dipole Forces The intermolecular forces between  polar molecules  tend to be  stronger   with  Greater overall dipole moments What could you predict about the  boiling point of these substances?
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Intermolecular Forces? Even 
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/03/2011 for the course CHEM 151 taught by Professor Staff during the Fall '08 term at Arizona.

Page1 / 33

Week 11 - GeneralChemistry CHEM151 Week 11 UA GenChem...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online