Unit 3 Part 7 - 2.2.8-9 Intermolecular forces Flashcards
3MAY25
Intra meaning?
Within (bonds)
Inter meaning?
Between
What does intermolecular forces mean?
Forces of attraction between molecules
What do intermolecular forces largely attract?
M.P and B.P
What does a stronger Intermolecular force mean?
Higher M.P and B.P
What is an induced dipole?
A temp shift of the electron cloud around a molecule in such a way that temporarily creates a dipole
Where does London dispersion forces exist?
Everywhere
What are the three factors that effect the size of London force?
- # of electrons
- Size/ volume of electron cloud
- Shape of molecule
How does the number of electrons effect the size of London force?
More electrons = Large attractive force
How does the size of the electron cloud effect the size of london force?
More electrons allow for more charge available to move around in molecule
How does shape of the molecule effect size of London force?
Longer chains have larger usable surface area
What are isomers?
Same chemical formula but dif shape
What molecules do dipole-dipole forces attract?
Polar
Why do D-D forces attract polar molecules?
B/c they have permanent dipoles
What is a special case of D-D forces?
Hydrogen bonding
When do hydrogen bonds happen?
Only when H is bonded to N, O, and F
What leads to a very strong attractive force to areas of high electronegativity?
When hydrogen loses its valence electrons in a covalent bond and all that’s left is a proton
What are all the intermolecular forces?
- London dispersion force
- Dipole - Dipole
- Hydrogen bonding
What non-polar
Equally sharing of electrons (symmetrical)
What is polar
Unequal sharing of electrons
( Creates D-D)
