Distingushing Intra-intermolecular Forces Flashcards
Intermolecular forces
They are BETWEEN molecules
Energy line,
1 (dispersion forces, non polar)
5 (dipole dipole, polar molecules)
20 (H-bond)
Intramolecular
They occur INSIDE
Energy line
400 single
600double
How do you calculate Ionic Bonds?
Increase with increasing charge density
At the top of the PT, smaller, tighter, high density, takes the least amount energy
At the bottom of the PT, larger, loose, low density, takes the most amount of energy.
Amount of charge/ size of atom
The types of bonds and what they carry
H-bond- has all three
Polar- dipole-dipole and instantaneous
Non polar- only instantaneous
What are dispersion forces?
- They are from the instantaneous dipoles which are formed by polar distributed electrons
- Occurs in all compounds but it is more dominant in non polar (symmetrical)
-As molecules increase in size, they grow to allow liquids and solids to be formed
What are dipole-dipole?
- Occur in permanent dipoles (polar compounds)
- they are related to size of the permanent dipole (EN)
As we head down the period table, the ___ compounds and ___ dispersion
Large compounds and more dispersion
Relationship between size of a compound and IMF is…
of electrons increase, and IMF increases
In electronegativity, NH(0.9), OH(1.4), HF (1.9). What does this mean about O-H attractions
They are stronger
Rank, NH3, H2O, HF
NH3<HF<H2O
What does NH3 mean?
3 h bonds but small EN
What about HF?
It is the largest EN
What about H2O?
It has a large EN, 2 H-bonds
What about OH?
It has multiple H-bonds in sugars that is why it is sticky!
What describes a hydrogen bonding
Must have a negative and positive attraction to form a molecule
What type of IMF is a non polar?
Dispersion
What is the type IMF for a polar?
Permanent dipole
What type of IMF is for N-H, O-H, H-F?
Hydrogen bonding
What type of IMF is for salts
Ionic
Boiling point
T in which molecules in a bulk achieve a vapor pressure greater than atm pressure and escape (bubbles)
Surface tension
A surface phenomenon in which an inward force reduces the surface area of a liquid ( beading up of water)
Capillary Action
Tendency of surface molecules to adhere to solid material surrounding the liquid (climbs)
Viscosity
Liquid to resist pouring because of IMF attraction to a bulk solution.
(Resistance to flow)
What are some characteristics of viscosity?
The colder the solid the higher the viscosity
(Low temp)
The larger the solid the most viscous
