VESPR theory Flashcards
What does VESPR stand for?
Valence Shell Electron Pair Repulsion
What is the VESPR theory used to do?
Predict the shape of polyatomic molecules
What does the theory assume?
That electron pairs within atoms will arrange themselves as far apart as possible in order to minimise repulsion.
What will the groups of atoms take up?
BASIC shapes according to the specific numbers of electron pairs (numbers of atoms attached)
For 2 electron pairs, what would the basic shape be?
Linear
For 3 electron pairs, what would the basic shape be?
Trigonal planar
For 4 electron pairs, what would the basic shape be?
Tetrahedral
For 5 electron pairs, what would the basic shape be?
Trigonal bipyramidal
For 6 electron pairs, what would the basic shape be?
Octahedral
What is the bond angle for a linear shape?
180
What is the bond angle for a trigonal planar shape?
120
What is the bond angle for a tetrahedral shape?
109.5
What are the bond angles for a trigonal bipyramidal shape?
90
120
What is the bond angle for a octahedral shape?
90
What equation is used to calculate the number of electron pairs?
No of outer electrons on central atom+ no of electrons donated by bonded atoms /2