Chapter 9: Molecular Geometry and Bonding Theories

Question 1

What are the bond angles in a tetrahedron molecular shape?

Answer 1

109.5 degrees

Question 2

what is the MOLECULAR geometry for a molecule with THREE bonding domains and no non-bonding domains?

Answer 2

trigonal planar (flat)

Question 3

Does bond enthalpy go up or down as bond order goes up?

Answer 3

up (as bond enthalpy is the energy needed to break 1 mole’s worth of a given bond)

Question 4

what is the MOLECULAR geometry for a molecule with THREE bonding domains and TWO non-bonding domains?

Answer 4

t shaped

Question 5

What are the bond angles in a linear molecular shape?

Answer 5

180 degrees

Question 6

what is the MOLECULAR geometry for a molecule with FOUR bonding domains and no non-bonding domains?

Answer 6

tetrahedral

Question 7

what is the MOLECULAR geometry for a molecule with FOUR bonding domains and ONE non-bonding domains?

Answer 7

seesaw

Question 8

What are the bond angles in a trigonal planar molecular shape?

Answer 8

120 degrees

Question 9

What are the bond angles in a trigonal BI-pyramid molecular shape?

Answer 9

120 degrees and 90 degrees

Question 10

what is the ELECTRON geometry for a molecule with TWO electron domains?

Answer 10

linear

Question 11

Where do non-bonding electron pairs live in the octahedron molecular shape?

Answer 11

In the axial (up and down) plane

Question 12

what is the MOLECULAR geometry for a molecule with FIVE bonding domains and no non-bonding domains?

Answer 12

trigonal bypyramid

Question 13

Does a bond order of 1/2 mean that 1/2 of a bond will form between two atoms?

Answer 13

Not necessarily. I means that the atoms involved in this particular molecular orbital are slightly more stable/have slightly less energy than they do as two separate atoms.

Question 14

what is the MOLECULAR geometry for a molecule with FIVE bonding domains and THREE non-bonding domains?

Answer 14

linear

because the non-bonding domains occur equatorially

Question 15

Do anti-bonding originals cancel out the bond-stregnthening effects of bonding orbitals?

Answer 15

Yes, especially if the electrons in non-bonding orbitals outnumber the electrons in bonding orbitals.

Question 16

Which range of bond order values tell you that some level of bonding is likely to occur?

Answer 16

All bond order values greater than 0 indicate that some level of bonding is likely to occur

Question 17

Where do non-bonding electron pairs live in the trigonal bipyramid molecular shape?

Answer 17

in the equatorial (around) plane

Question 18

What are the bond angles in a octahedral molecular shape?

Answer 18

90 degrees

Question 19

According to molecular orbital theory, how does energy predict whether bonds will occur between atoms?

Answer 19

The energy of involved in having electrons in bonding molecular orbitals is LOWER than the energy involved in keeping the electrons in separate, regular regular atomic orbitals

This is true even when some electrons wind up in non-bonding molecular orbitals, provided the non-bonding orbitals don’t outnumber the bonding orbitals.

Question 20

Is bond order the only factor that plays into bond enthalpy and bond length?

Answer 20

No, Things like Zeff and orbital overlap also play a role

Question 21

Can you have fractions for bond orders?

Answer 21

Yes

Question 22

what is the MOLECULAR geometry for a molecule with TWO bonding domains and ONE non-bonding domains?

Answer 22

bent

Question 23

what is the ELECTRON geometry for a molecule with FOUR electron domains?

Answer 23

tetrahedral

Question 24

How/why does increasing the number of electrons in an anti-bonding orbitals DECREASE a molecule’s bond stability?

Answer 24

If anti-bonding electrons outnumber the bonding electrons, the net effect is that a bond is LESS likely to occur (b/c the wave functions for the electrons aren’t lining up just right to give rise to CONSTRUCTIVE wave combination)

Question 25

what is the MOLECULAR geometry for a molecule with THREE bonding domains and ONE non-bonding domains?

Answer 25

trigonal pyramid

Question 26

what is the MOLECULAR geometry for a molecule with four bonding domains and TWO non-bonding domains?

Answer 26

square planar (flat)

because the non-bonding domains are axial

Question 27

what is the MOLECULAR geometry for a molecule with TWO bonding domains and TWO non-bonding domains?

Answer 27

bent

Question 28

what is the MOLECULAR geometry for a molecule with FIVE bonding domains and ONE non-bonding domains?

Answer 28

square pyramid

because the non-bonding domain is axial

Question 29

Does bond energy get larger with higher bond order or smaller????

Answer 29

larger???

Question 30

what is the equation for bond order?

Answer 30

[(# of bonding electrons - # of NON bonding electrons)]/2

Question 31

what is the MOLECULAR geometry for a molecule with TWO bonding domains and no non-bonding domains?

Answer 31

linear

Question 32

Does bond stability go stronger with higher bond order or weaker?

Answer 32

stronger

Question 33

what is the ELECTRON geometry for a molecule with THREE electron domains?

Answer 33

trigonal planar (flat)

Question 34

Does bond length get longer or shorter as bond order increases?

Answer 34

shorter;

Question 35

what is bond order supposed to describe?

Answer 35

stability of chemical bonds between a pair of atoms

or the likelihood that bonds will form

NOT the number of bonds

Question 36

what is the ELECTRON geometry for a molecule with FIVE electron domains?

Answer 36

trigonal BIpyrimidal

Question 37

what is the MOLECULAR geometry for a molecule with SIX bonding domains and no non-bonding domains?

Answer 37

octahedral

Question 38

what is ‘delocalization’ of pi bonds meant to describe in the hybridization model?

Answer 38

the fact that when a molecule has resonance, the depiction of its double bonds is supposed to represent an average bond length/location for the electrons involved in the double bonds

Question 39

what is the ELECTRON geometry for a molecule with SIX electron domains?

Answer 39

octahedral