Liquids and Gases

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Liquids and Gases
Fred J. Grieman
Intermolecular Forces
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• Chemical Bonding
• covalent bonding sharing electrons
• ionic bonding Ep Q1Q2/r
• MUCH
  ________
• Ep

________
Shorter range weaker!
_____________
Ar Ar Whats that about?
______ created By combination
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2) ________ Ep

• 3) _________________
• atom or molecule with ? 0
• ?ind ? ? ? ? ___________
• ? ? _______
• ?(He) 0.20 Å3 ?(Ar) 1.6 Å3
• ? ?_________ Why?
• __________________________________________________
  _________

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• ?

a) ____________________ Ep ? _________ Ep ?
_________
e- density
?
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b) _________________ Ep ? __________
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Why do ________________________? must be some
_____________ ________________________________

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______________
Induced dipole Ep ?
-______________ ? - ______________ ____________
_______________
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Repulsive Forces Coulombic Ep
________________ Pauli repulsion modeled as Ep
________ very, very short range Gases Ideal
Gases no intermolecular force ? P RT/ V

____________________ Real Gases have
intermolecular forces One model
___________________________ Equation of state
____________________________


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Liquids Simplest Noble Gas Liquefication (He,
Ar, ) Very cold temperatures Ep
______________________ Pauli
London Dispersion
For He, re ____, De ______
kJ/mol Compare H2 ______
______ kJ/ mol (chemical bond)
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Measure of attractive forces via
_________________ Liquid energy (heat) ?
Gas Equilibrium Gas pressure ____________
f(temperature) Temperature when Vapor pressure
surrounding pressure _____________ Surrounding
Pressure 1 atm ____________________ The
___________ the Normal Boiling Point the
__________ the energy required to liquid ? gas
the ________________________________
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Hydrogen Bonding Strong Dipole-Dipole
interaction _____________________________________
___________________ ? ____________________
_________________ ? _____________________
_____________________ ___ kJ/mol compared to ___
kJ/mol for typical dipole-dipole
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Using boiling point again to indicate
intermolecular force