diversity of matter and chemical bonding cont. Flashcards
INTRAMOLECULAR BOND
covalent bond; bonds within the molecule
INTERMOLECULAR FORCES
forces of attraction between molecules
- London Dispersion Forces (LDF)
- Dipole-Dipole Forces (DD)
- Hydrogen Bonding (H-Bond)
Which is strong?
Intermolecular forces
Intramolecular forces
Intramolecular forces (Covalent bonds)
London Dispersion Forces (LDF)
Special type of vanderwaals force; molecules feel attraction because protons of one feel attraction to electrons of another and vice versa.
How to calculate LDF
- add up atomic # of each atom in moelvule
What does low and high LDF mean?
low LDF: low magnitude
high LDF: high magnitude
what molecules have LDF?
all molecules, polar or non-polar
Dipole-Dipole Forces (DD)
the dipole of one polar molecule aligns with dipoles of neighbouring molecules in 3-D
- Slight- is attracted to the slightly+ of another dipoled
Hydrogen Bonding (HB)
strongest of the intermolecular forces
Is HB a DD?
yes; special type where a H nucleus is simultaneously attracted to the electron of its intramolecular bond, and a lone electron pair on an adjacent molecule
what qualifies as an HB?
H atom directly bonded to N, O , F
Best way to determine presence of intramolecular forces
- create a 3-D image of the molecule
- create a checklist
LDF:
DD:
HB:
Kinetic Molecular Theory
- All matter is made up of tiny particles
- These particles are in constant motion
- As these particles are in motion, they do interact with each other
- The particles exhibit attractive forces over short distances (intramolecular forces)
Solid
- only vibrational motion
- flexion within bond length
- Restricted particles movement
Liquid
- vibrational and rotational motion
- lightly separated
Gas
- translational motion
- highest energy particles
Order the states of matter from lowest to highest in IMF
Gas
Liquid
Solid (holds particles together)
order states from lowest to highest in Ek
Gas
liquid
solid
what happens to IMF when changing from solid to liquid
partially overcome IMF
what happens to IMF when changing liquid to gas
completely overcome IMF
properties when condensing
- particles slow down
- interactions inc.
- IMF develop
properties when freezing
- stronger IMF develop
273.15°C
absolute zero; all substances are solid
molecules with low MP/BP
low IMF
low amount of energy needed to overcome
molecules with high MP/BP
high IMF
Solubility statement
like dissolves like
polar solvents dissolve….
polar solutes
non-polar solvents dissolve…
non-polar solutes
are hydrocarbons polar or non-polar
all hydrocarbons are non-polaris CO
is CO2 soluble in water>
no
-water molecules are too attracted
-keep CO2 out, can’t fit in
