Exam 1 Flashcards
What are intermolecular forces?
attractive forces between molecules
What are intramolecular forces?
forces that hold atoms together in a molecule
Are intermolecular or intramolecular forces weaker?
intermolecular forces
What is a major determining factor in boiling point, melting point, heat of vaporization and heat of fusion?
intermolecular force
if a molecule is in a solid state…
interactive force > kinetic energy
if a molecule is in liquid state…
interactive force and kinetic energy are about equal
if a molecule is in gas state…
kinetic energy > interactive force
What happens to the boiling point when the atomic number goes up?
boiling point increases
What happens to the attraction of atoms as they get bigger?
stronger attraction
What happens to boiling/melting point as the attraction gets stronger?
the boiling point and melting point both are higher
What is the London Dispersion Force (LDF)?
intermolecular force between non polar molecules or atoms caused by presence of temporary dipoles
What happens to LDF when molecule size increases?
LDF increases
What is the weakest of all intermolecular forces?
London Dispersion Force
What is dispersion?
a momentary shift in electron density
How are temporary dipoles created?
a momentary shift in electrons
What are the two main factors that affect the strength of dispersion factors?
atom size and atom shape
What is dipole-dipole interaction?
force present between polar molecules
What is a hydrogen bond?
an H+ atom bonded to an O, F, or N atom (highly electronegative)
What is the stronger dipole-dipole interaction?
a hydrogen bond
What happens to molar mass if you decrease boiling point?
molar mass decreases
What is an ion-dipole interaction?
attractive force between an ion and molecule that has a permanent dipole
What is a sphere of hydration?
cluster of water molecules surrounding an ion in an aqueous solution
How does a sphere of hydration form?
ion dipole interaction
What is sublimation?
a phase change from solid to gas
