Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
Lewis Structure |
shows atoms and bonds, but not spatial (3D) orientations |
|
|
Molecular Models |
show orientations and bond angles; help us understand physico-chemical properties |
|
|
Bond Angle |
angle defined by covalent bonds between three adjacent atoms |
|
|
Molecular Geometry |
shape defined by lowest energy 3-D arrangement of atoms |
|
|
Valence Shell Electron Pair Repulsion Theory (VSEPRT |
geometric arrangement of electron pairs around atoms based on minimizing repulsion energy |
|
|
Electron Pair Geometry |
Spatial arrangement of bonding electron pairs and lone pairs (non-bonding e-) of valence electrons |
|
|
Molecular Geometry |
the relative arrangement of atoms (Bonding pairs) in molecules |
|
|
To determine electron pair geometry |
1. draw lewis structure 2. from lewis structure determine steric number 3. determine the best spatial arrangement of bonding and lone pairs of electrons |
|
|
Steric Number |
the number of atoms bonded to the central atom + number of lone pairs bonded to central atom |
|
|
Electron Pair Geometry |
5 types linear: 180 degrees trigonal planar: 120 degrees tetrahedron: 109.5 degrees trigonal bypyramidal: 90-120 Octahedron: 90 degrees |
|
|
Electron Pair Repulsions |
lone pair-- lone pair = greatest repulsion long pair--bonding pair= second greatest bonding-- bonding= least repulsion double bonds exert more repulsion than single bonds bond angles around central atom decreases as repulsive forces increase |
|
|
Dipole Moment |
measure of degree of charge separation in a molecule |
|
|
Polar Molecule |
1. Molecule must have polar bonds ( covalent b/t atoms with a change in enthalpy) 2. orientation of polar bonds results in charge separation from one part of the molecule to another |
|
|
Bond Dipole |
separation of a charge within a covalent bond |
|
|
Polar molecule |
have nonzero dipole moments vectors of bond dipoles sum > zero |
