Topic 14

Question 1

What are sigma bonds?

Answer 1

The head to head overlap of atomic orbitals with its electron density concentrated along the internuclear axis

Question 2

What are pi bonds?

Answer 2

The sideways overlap of p orbitals with its electron density concentrated above and below the internuclear axis

Question 3

If there is a double bond how many sigma and pi bonds does it have?

Answer 3

1 sigma, 1 pi

Question 4

If there is a triple bond how many sigma and pi bonds does it have?

Answer 4

1 sigma 2 pi

Question 5

Draw the structure of NO3-

Question 6

Draw the structure of CO32-

Question 7

Draw the structure of SO42-

Question 8

Draw the structure of ozone

Question 9

What are resonance structures?

Answer 9

Structures where there is more than one place for the multiple bond

Question 10

What does formal charge tell you?

Answer 10

• Which lewis structure is preferred when more than one is possible
• the charge that an atom would have if all the atoms had the same electronegativity

Question 11

Which formal change value is the best?

Answer 11

The one closest to 0

Question 12

Formula charge formula

Answer 12

FC= VE-NE-1/2 BE

VE= valence electrons
NE= non bonding electrons
BE= bonding electrons

Question 13

What is the formula charge for ions?

Answer 13

It is always the overall charge on the ion

Question 14

VSPER theory

Answer 14

• predicts the shape of the molecules ( MDG)
• electron pairs repel each other as far apart as possible
• EDG = the number of electron domains

Question 15

5 electron domains ( 5 bonding domains, 0 lone)

Answer 15

• trigonal bipyramidal

- 90 degrees / 120

Question 16

5 electron domains ( 4 bonding domains , 1 lone)

Answer 16

• see saw

- <90/<120

Question 17

5 electron domains ( 3 bonding domains, 2 lone)

Answer 17

• T shaped

- < 90

Question 18

5 electron domains ( 2 bonding domains , 3 lone domains )

Answer 18

• linear

- 180 degrees

Question 19

6 electron domains ( 6 bonding domains , 0 lone)

Answer 19

• octahedral

- 90 degrees

Question 20

6 electron domains ( 5 bonding domains, 1 lone domain)

Answer 20

• square pyramidal

- < 90

Question 21

6 electron domains ( 4 bonding, 2 lone)

Answer 21

• square plannar

- 90 degrees

Question 22

Equations for destruction of ozone by NO

Answer 22

NO. + O3 = NO2. + O2

NO2. + O3 = NO. + 2O2

Question 23

Equations for the destruction of ozone for CFCs

Answer 23

CCl2F2 – CClF2. + Cl. ( by U.V.)

Cl. + O3 = ClO. + Cl.
ClO. + O. = Cl. + O2

Question 24

Hybridisation