6.4 Hydrogen bonds Flashcards
1
Q
what are hydrogen bonds formed between?
A
a lone pair of electrons and a hydrogen atom attached to:
oxygen
nitrogen
fluorine
2
Q
what is a hydrogen bond?
A
attraction between a lone pair of electrons on an electronegative atom and a hydrogen atom
3
Q
order of increasing strength of intermolecular forces
A
London forces
permanent dipole-dipole
hydrogen bonds
4
Q
why is ice less dense than water?
A
hydrogen bonds hold water molecules further apart in an open lattice stricture in ice
therefore ice is less dense and can float
5
Q
why does water have a high melting and boiling point?
A
hydrogen bonds are extra to London forces
hydrogen bonds are stringer than London forces
more energy is needed to overcome the hydrogen bonds
