Intermolecular Forces Flashcards
Polarizabaility
The way the change distribution in a molecule can be distored to induce a temporary dipole
Boiling points are based on what?
The strength of the intermolecular forces (The stronger the forces the higher the boiling point)
When the dipole moment increase so does what?
The boiling point
Vapor pressure increase as _____ inceases until its equals the external pressure over the liquid ( Which causes liquids to boil)
Temperature
Why do gases expand?
Since gases are widely separated particles their average energy of attraction between the particles is smaller than average energy of the particles and since there isnt strong attraction between the particles the gas expands
Boiling points of halogens & noble gases increases when ______ increase
Molecular weight
When the polarityof a molecule increase what happens?
Its intermolecular attraction increases as well
Dipole - Dipole forces are effective when what?
Polar molecules are very close to another
Polar molecules are dipoles because they have what?
Partial postive ends & partial negative ends
Hydrogen bonds
Intermolecular attraction between the hydrogen atom in a polar connecting to a nearby electronegative atom in another bond
Kinetic Energy does what?
keeps particles apart & moving ( Also depends on Temp.)
Phase Changes
Substances change phases
Cohesive forces are the ___________ of the molecule
Intermolecular forces
The strength of dispersion forces increases as _______ increases
Atomic or Molecular size
Small polar molecular experience what?
High dipole - dipole attraction
Intermolecular Forces
Are forces that exist between molecules
Which is stronger hydrogen bonds or dispersion forces or Dipole - Dipole foces?
Hydrogen bonds are stronger than disperison forces & dipole - dipole forces
Dipole - Dipole increases as the _______ of the molecule increases
Dipole Moment
Critical Pressure
The pressure required to bring about liquidifcation at the critical temperature
Substances with high vapor pressure evaporate _____ than substances with lower vapor pressure
Quicker
Increasing ____ on a gas forces the molecules closer together, which increases the strength of the intermolecular forces of attractions
Pressure
The heat of sublimation is the sum of what?
The sum of heat of fusion & heat of vaporization
Which intermolecular forces are strongest and which is weakest?
Solid < Liquids < Gases ( Strongest to weakest)
Adhesive forces are forces between the _______ & the ______
Liquid & the tube
When two substances have the same weight & shape then their disperison forces are what?
Equal