chem chapter nine

Question 1

how can we think of bonding?

Answer 1

overlapping of electrons clouds
sharing of electrons in empty orbitals

Question 2

hybrid orbitals or valance bond theory

Answer 2

-s, p, and d orbitals mix
-they have new shape
-the new hybrid orbitals are degenerate
-they get a new orbital designation

Question 3

hybridization: 2 electron groups

Answer 3

sp

Question 4

hybridization: 3 electron groups

Answer 4

sp^2

Question 5

hybridization: 4 electron groups

Answer 5

sp^3

Question 6

hybridization: 5 electron groups

Answer 6

sp^3d

Question 7

hybridization: 6 electron groups

Answer 7

sp^3d^2

Question 8

sigma bonds

Answer 8

-result from the HEAD TO HEAD overlap of orbitals
-fist type of bonds made in an electron group
-involves s or hybrid orbitals

Question 9

pi bonds

Answer 9

-results from the SIDE TO SIDE overlap of p orbitals
-they only appear in double or triple bonds
-do not involve any hybrids

Question 10

which is stronger, sigma or pi bonds?

Answer 10

sigma

Question 11

molecular orbit theory (MO)

Answer 11

deals better with delocalized electrons (resonance), molecules with unpaired electrons, and bond energies

Question 12

molecular orbits

Answer 12

-the number of molecular orbits is = to the total number of atomic orbitals contributed by the combinations of the atoms
-holds two electrons per orbital
-fill orbitals with the same rules
-indicate where electrons are likely to be found
-can be thought of as combinations and differences

Question 13

one MO results from the addition of the 1s orbital

Answer 13

-known as bonding molecular orbital
-the σ 1s
-bonding is stabilized
-bonding orbitals are lower in energy than atomic orbitals

Question 14

one MO results from the difference of the 1s orbital

Answer 14

-known as antibonding
-it is also a σ
-the orbital designation is σ1s*
-antibonding is higher in energy than the atomic orbitals
-the molecule is destabilized

Question 15

bond order for MO

Answer 15

(number of bonding e-) - (number of antibonding e-)/ 2

Question 16

homonuclear diatomic molecules

Answer 16

atoms with the same elements

Question 17

sigma bonds overlap

Answer 17

horizontal, head to head

Question 18

pi bonds overlap

Answer 18

vertically, side to side

Question 19

boron is shown to be

Answer 19

paramagnetic (unpaired electrons)

Question 20

S-P mixing atoms

Answer 20

B2, C2, N2

Question 21

normal order for MO energy diagram (start from the bottom)

Answer 21

sigma2s, sigma2s, sigma2p, pi2p, pi2p, sigmasp*

Question 22

s-p mixing MO diagram order

Answer 22

sigma2s, sigma2s, pi2p, sigma2p, pi2p, sigma2p*

Question 23

atoms with higher effective nuclear charge (Zeff) will have lower

Answer 23

energy valence orbitals