Chapter 6

Tetrahedral

109.5 degrees 4 domains

Trigonal planar

120 degrees 3 domains

Linear

180 degrees 4 electron domains 2 lone pair

bent

4 domains 2 lone pairs

In the molecule KrBr2 there are ____ electron domains surrounding the central Kr atom; ____ bonding pair(s) and 3 lone pair(s). The molecular geometry around the central atom is therefore _____.

5 2 3 linear

seesaw

5 domains 1 lone pair

square planar

6 domains 2 lone pairs

Trigonal bipyramidal

90 and 120 degrees 4 domains 1 lone pair

Axial bonds and equatorial bonds

90 degrees

Octahedral

90 degrees 6 domains

ABx

A= Central atom structure B= Surrounding atom x= number of surrounding atoms

Triple bond

Composed of 2 sigma bonds and 2 pi bonds

Which statement correctly describes the basic principle of VSEPR theory?

Each group of valence electron around a central atom is located as far from the others as possible.

intermolecular forces

Intermolecular forces are the weak forces of attraction found between the individual molecules of a molecular covalent substance.

Bond angles associated with each electron domain geometry

The trigonal bipyramidal system has 2 dif bond angles. A species w/ 3 electron domains will exhibit an ideal bond angle of 120. A bond angle of 180 is observed for a linear system.

In an ABx molecule, the angle between two adjacent A-B bonds is called the ______ angle. This angle is determined by the number of __________ domains or groups surrounding the central atoms.

bond electron

The molecular shape of a species, which is the arrangement of the bonded atoms around the central atom, determined not only by the number of ____ electron domains that join the atoms, but by the number of ____ electron domains as well, since these electrons also occupy space.

bonding nonbonding

The electron-domain geometry of a species is the arrangement of electron _______ around the central atom, whereas the molecular geometry is the arrangement of bonded ________. Two species with the same electron- domain geometry may have different molecular geometries.

domains atoms

A 5-electron group system (shown) has two different types of positions for substituents. The three positions marked "1" form a trigonal plane about the central atom and are called__________ positions, while the two positions marked "2" are ________________ positions.

equatorial axial

Net dipole moment

ex: NBr3, CH2Cl2

Molecular shape is determined by the number of electron domains around a central atom, where an electron domain may be a(n) __________ electron pair or any ___________ between two atoms.

lone bond

Consider the molecule CCl4. Each C-Cl bond in this molecule is __________ because the electronegativity difference between C and Cl is equal 0.5. Since CCl4 is tetrahedral in shape and symmetrical, the individual bond dipoles ___________ and the molecule is ______________ overall.

polar cancel nonpolar