Bonding: Shapes of molecules Flashcards
what is the name of the theory which helps to predict the shapes of molecules?
- electron pair repulsion theory
- valence shell electron pair repulsion theory
what two conclusions can we draw from this theory?
- each pair of electrons around an atom will repel each other as far as possible
- pair of electrons will take up positions as far apart as possible to minimise repulsion
what are the two types of electron pairs?
- bonding pairs
- lone pairs
what is a bonding pair?
two shared electrons in a covalent bond
what is a lone pair?
a pair of electrons not involved in bonding
why do lone pairs repel more than bonding pairs?
because they are more compact
what is name of shape and bond degree when there are 2 bp?
linear - 180
what is name of shape and bond degree when there are 3bp?
trigonal planar - 120`
what is name of shape and bond degree when there are 2 bp and 1 lp?
bent - 118
what is name of shape and bond degree when there are 4 bp?
tetrahedral - 109.5
what is name of shape and bond degree when there are 3 bp and 1 lp?
trigonal pyramid - 107
what is name of shape and bond degree when there are 2 bp and 2 lp?
bent - 104.5
what is name of shape and bond degree when there are 5 bp ?
trigonal pyramid - 120/ 90
what is name of shape and bond degree when there are 4 bp and 1 lp?
see-saw - 119/89
what is name of shape and bond degree when there are 3 bp and 2 lp?
trigonal planar or T shape - 120 or 89