Chapter 9

Question 1

What are bond angles?

Answer 1

angles made by the lines joining the nuclei of atoms

Question 2

What 2 things determine the size and shape of the molecule?

Answer 2

bond angles and bond lengths

Question 3

What is a tetrahedral?

Answer 3

4 corners, 4 faces, each an equilateral triangle

Question 4

What is a bent shape?

Answer 4

if atom A lies above 2 atom Bs

Question 5

What is a trigonal planar?

Answer 5

if atom A is on the same plane as atom Bs

Question 6

What is a trigonal pyrimidal?

Answer 6

if atom A lies above the plane of 3 atom Bs

Question 7

What are the 5 basic molecular arrangement shapes?

Answer 7

linear AB2 | trigonal pyramidal AB3 | tetrahedral AB4 | trigonal bipyramidal AB5 | octahedral AB6

Question 8

What does VESPR stand for?

Answer 8

valence shell electron pair

Question 9

What is the VESPR model?

Answer 9

based on the idea that electron domains are negatively charged and repel one another

Question 10

What is an electron domain?

Answer 10

a region in which the bonding-pair electrons are found

Question 11

What is the best arrangement of a given number of electron domains?

Answer 11

one that minimizes the repulsions among them

Question 12

What is electron domain geometry?

Answer 12

arrangement of electron domains about the central atom of an ABn molecule/ion (includes lone pairs)

Question 13

What is molecular geometry?

Answer 13

an arrangement of the atoms

Question 14

How can we determine the molecular geometry?

Answer 14

based on how many electron domains there are due to bonds

Question 15

What is the effect of non-bonding electrons on bond angles?

Answer 15

exert a greater repulsive force on neighboring electron domains = compress (decrease) bond angles

Question 16

What is the effect of multiple bonds on bond angles?

Answer 16

multiple bonds = larger electron domains = exert greater repulsive force on neighboring electron domains

Question 17

What is the most stable 5 electron domain shape and why?

Answer 17

trigonal bipyramidal due to less repulsion

Question 18

What is the most stable 6 electron domain shape and why?

Answer 18

octahedron, all angles are 90

Question 19

How are the shapes of larger molecules determined?

Answer 19

determine VESPR shape of each central atom

Question 20

What does the dipole moment depend on for molecules with 2< atoms?

Answer 20

both the polarities of the individual bonds and the geometry of the molecule

Question 21

What indicates if a molecule with 2< atoms is nonpolar?

Answer 21

dipole vectors point at OPPOSITE directions

Question 22

What indicates if a molecule with 2< atoms is polar?

Answer 22

dipole vectors point at the SAME direction

Question 23

What is the valence bind theory?

Answer 23

bonding electron pairs are concentrated in the regions between atoms | nonbonding e- pairs lie in regions in space

Question 24

What is Lewis’s theory?

Answer 24

covalent bonding happens due to the concentration of electron density between 2 nuclei from the atoms sharing electrons

Question 25

What is the optimum distance between 2 nuclei in a covalent bond?

Answer 25

when the attractive forces between opposite charges are balanced by the repulsive forces between like charges