14.2 Hybridization (HL)

Question 1

Hybridization

Answer 1

Mixing of orbitals in a particular atom to produce a new set of orbitals that have characteristics of the original but are better arranged for covalent bonding

Question 2

Why does hybridization allow better covalent bonding?

Answer 2

Due to allowance for greater overlapping

Question 3

What features do hybrid orbitals share that are different from parent orbitals?

Answer 3

Exactly the same:

• Shape
• Orientation
• Energy in space

Question 4

What is configuration of carbon (including 3 p orbitals) and hence when does excitation occur?

Answer 4

1s2 2s2 2px1 2py1 and 2pz0.

Excitation occurs when electron is promoted from 2s2 to 2pz0

Question 5

What is hybridization in tetrahedrals?

Answer 5

sp3 hybridization (1 s and all 3 p orbitals)

Question 6

When is energy that is required to promote electrons made up for eg. carbon

Answer 6

When C atom forms 4 new bonds, as bond-making releases energy (exothermic)

Question 7

Are bonds equal in hybridization?

Answer 7

Yes. Bonds are otherwise not normally equal as 2s orbital is lower in energy

Question 8

Sp3 hybridization

Answer 8

When 4 hybrid orbitals are formed. Tetrahedral arrangement to minimize repulsion

Question 9

How would one draw arrow boxes to represent carbon to sp3 hybridization?

Answer 9

Normally carbon has 2 arrows in 1s2, 2s2 and two single arrows in 2p2 however AFTER hybridization, it changes to 2 arrows in 1s2 and 4 boxes in sp3, each with one arrow

Question 10

Which orbitals will overlap in methane? Bond angle

Answer 10

Four sp3 orbitals overlap head on with s orbital of hydrogen to form 4 sigma bonds.
Bond angle= 109.5

Question 11

sp2 hybridization

Answer 11

1s and 2 p orbitals are involved. Eg. in alkenes

Question 12

How does hybridization work in sp2?

Answer 12

One 2p orbital doesn’t participate as its a pi bond so there will be a full 1s2, a lone 2p and a single arrow in 3 boxes of sp2

Question 13

Which bond is hybridized?

Answer 13

Only sigma bonds

Question 14

Describe hybridized ethene C2H4

Answer 14

2 orbitals will bond with s orbital of hydrogens, 1 p orbital of carbon will bond with one of the other carbon and there will be a lone p orbital standing on both carbons.

Question 15

sp hybridization

Answer 15

When there is triple bond so there are 2 pi bonds and 1 sigma bond hence only 1 p orbital participates

Question 16

Describe hybridized structure of ethyne C2H2

Answer 16

Orbitals of carbon will react with other carbon and hydrogen but there will be 2 lone p orbitals

Question 17

What can be correlated to hybridization? Give examples

Answer 17

Electron domain geometry

• Linear has sp
• Trigonal planar has sp2
• Tetrahedral has sp3

Question 18

Which is higher in energy? 2p or sp

Answer 18

2p orbitals