Chapter 5

Question 1

ionic molecular structure

Answer 1

metal/nonmetal (+- not sharing of e-)

Question 2

covalent molecular structure

Answer 2

nonmetal/nonmetal (partial charges-delta-sharing of e-)

Question 3

Lewis octet rule

Answer 3

• elements like to have 8 e- in their outermost shell (isoelectronic w/ noble gas)
• use a dot to represent e- in valence shell of an element
• elements want to share their unpaired electrons so as to reach an octet (stable noble-gas electronic configuration)
• H and F are always terminal. They are never in the middle of molecules. They are always on the oustide of molecules. They cannot make more than one bond.
• Element with most unpaired electrons is in the middle of the molecule to facilitate bonding
• always use unpaired valence e- for bonding

Question 4

Lewis Octet Rule Exceptions

Answer 4

1) H2 or H in general, only can ever have 2e-
2) Group 3A elements B, Al, Ge, In…will only have 6e- surrounding after bonding
3) Elements with d-orbitals…Expansion of octets: occurs w/ elements in n>/=3 because they have d-orbitals that they can use (THIS NEVER HAPPENS WITH C,N,O,F,)

Question 5

formal charge

Answer 5

charge on an element in a molecule. the sum of all the charges must equal the charge on the molecule.

• small formal charge is preferred over large formal charge, a formal charge of zero is the most preferred
• if an element shares all of its unpaired valence e-s, it will always have a formal charge=ZERO

Question 6

formal charge equation

Answer 6

of valence e-s-(#of lone pair e-+#of bonds)

Question 7

VSEPR

Answer 7

Valence Shell Electron Pair Repulsion
-because of repulsions between bonding e- and lone pairs of e-, molecules oriente themselves in 3D space to minimize these repulsions
Two ways to describe them: electronic geometry and molecular geometry

Question 8

electronic geometry

Answer 8

name of geometry where both atoms and lone-pairs of e- are considered part of the shape=defines the shape

Question 9

molecular geometry

Answer 9

still have electronic shape, but now none of geometry is with respect to just atoms

Question 10

2-groups (2 element groups)

Answer 10

Electronic: linear
Molecular: linear
180 degrees

Question 11

3-groups (3 element groups)

Answer 11

Electronic: trigonal planar
Molecular: trigonal planar
120 degrees

Question 12

4-groups (4 element groups)

Answer 12

Electronic: tetrahedral
Molecular: tetrahedral
109.5 degrees

Question 13

5-groups (5 element groups)

Answer 13

Electronic: triganol bipyramidol
Molecular: triganol bipyramidol

Question 14

6-groups (6 element groups)

Answer 14

Electronic: octohedral
Molecular: octohedral

Question 15

3-groups (1 lone pairs and 2 elements)

Answer 15

Electronic: triganol planar
Molecular: bent

Question 16

4-groups (1 lone pair, 3 elements)

Answer 16

electronic: tetrahedral
molecular: triganol pyramidal

Question 17

4-groups (2 lone pairs, 2 elements)

Answer 17

electronic: tetrahedral
molecular: bent

Question 18

5-groups (1 lone pair, 4 elements)

Answer 18

electronic: triganol bipyromidal
molecular: see-saw

Question 19

5-groups (2 lone pairs, 3 elements)

Answer 19

electronic: triganol bypyromidal
molecular: T-shaped

Question 20

5-groups (3 lone pairs, 2 elements)

Answer 20

electronic: triganol bipyramidal
molecular: linear

Question 21

6-groups (1 lone pair, 5 elements)

Answer 21

electronic: octahedral
molecular: square pyramidal

Question 22

6-groups (2 lone pairs, 4 elements)

Answer 22

electronic: octahedral
molecular: square planar