MR: Electronegativity And Intermolecular Forces Flashcards
What are permanent dipole bonds
When polar molecules cause weak electrostatic forces of attraction between molecules
What are Instantaneous dipole - induced dipole bonds?
How do they come about? Lol
These forces cause all atoms and molecules to be attracted to each other.
Electrons in charge clouds are always moving quickly, at any one moment the electrons are likely to be more on one side than the other, this is a TEMPORARY DIPOLE.
The dipole can make another dipole in the opposite direction on a neighbouring atom, the two dipoles are attracted to each other.
How does the size and shape of a molecule affect the intermolecular forces formed?
The longer the carbon chain, the stronger the ID-ID forces between them, since there’s a larger surface area and more electrons to interact.
Branched chain molecules can’t pack closely together and also have smaller surface areas, so there are less forces between them.
What is a Hydrogen bond?
When hydrogen is covalently bonded to F, N or O, since they’re all very electronegative.
The bond is so polarised that the hydrogen atoms form weak bonds with lone pairs of elections on the F, N, O on the other molecules.
It is the strongest kind of intermolecular bond
What’s a dipole?
A difference in charge between the two atoms caused by a shift in electron density in the bond
