Chapter 3 - bonding

Question 0

State what a covalent bond is

Answer 0

Strong bond involving a shared paired of electrons

Question 1

State what an ionic bond is

Answer 1

The electrostatic forces of attraction between oppositely charge ions caused by electron transfer

Question 2

State what a metallic bond is

Answer 2

The strong electrostatic forces of attraction between the giant lattice of positive ions and the mobile sea of delocalised valence shell electrons

Question 3

Sate what a hydrogen bond is

Answer 3

(the strongest of the weak forces of attraction) the electrostatic forces of attraction between delta+ hydrogen of 1 molecule and delta- of another (NOF group)

Question 4

State what a dative covalent bond is

Answer 4

The strong bond formed when a lone pair of electrons is donated to an electron deficient species, once formed it behaves as a covalent bond

Question 5

State what a permanent dipole dipole force is

Answer 5

The weak electrostatic force of attraction between delta+ and delta- regions of polar molecules

Question 6

State what a van der Waals force is

Answer 6

(The weakest of the weak) very weak electrostatic forces of attraction between all molecules at all times, due to the changing position of the electron cloud, inducing temporary dipoles in adjacent molecules

Question 7

Define what is meant by the term electronegativity

Answer 7

For an associated covalent bond, the tendency for an atom to attract negative charge/electrons towards itself

Question 8

What can increase a van der Waals force?

Answer 8

The size of the molecule (larger), therefore the number of electrons

Question 9

When drawing a hydrogen bond/hydrogen attraction what 3 things must you include?

Answer 9

All lone pairs of electrons, delta+/-, hydrogen dotted to a lone pair of electrons

Question 10

Why does electronegativity decrease down a group?

Answer 10

There’s more inner electron shell shielding

Question 11

What 3 things does electronegativity depend upon?

Answer 11

Nuclear charge, distance between the nucleus and the outer shell electrons, inner electron shell shielding

Question 12

Why does electronegativity increase across a period?

Answer 12

There’s a greater nuclear charge pulling on the same outer shell of electrons; the atom becomes smaller

Question 13

When is a covalent bond polar?

Answer 13

When the difference in electronegativity is about 1

Question 14

When is a covalent bond pure?

Answer 14

When there is a very little/ no difference in electronegativity

Question 15

When is an ionic bond pure?

Answer 15

When there is a large difference in electronegativity >2.5

Question 16

When does an ionic bond have covalent character?

Answer 16

When there is a difference in electronegativity about 2

Question 17

What does the valence shell electron pair repulsion theory state?

Answer 17

Electron pairs repel each other as far apart as possible to minimise repulsion, lone pairs repel more

Question 18

Lone pairs decrease the bond angle by how much?

Answer 18

2.5 degrees

Question 19

Name the shape of the molecule when 2 atoms have equal repulsion and bond angle

Answer 19

linear, 180

Question 20

Name the shape of the molecule when 3 atoms have equal repulsion and the bond angle

Answer 20

trigonal planar, 120

Question 21

Name the shape of the molecule when there 4 atoms repelling equally and the bond angle

Answer 21

tetrahedral, 109.5

Question 22

Name the shape of the molecule when there are 3 atoms and 1 lone pair repelling and the bond angles

Answer 22

trigonal pyramidal 107

Question 23

Name the shape of the molecule when 5 atoms have equal repulsion and include the angles between the bonds

Answer 23

trigonal bipyramidal, 90 and 120

Question 24

Name the shape of the molecule when there are 4 atoms and 1 lone pair repelling

Answer 24

see-saw

Question 25

Name the shape of the molecule when 3 atoms and 2 lone pairs are repelling

Answer 25

T-shaped

Question 26

Name the shape of the molecule when 2 atoms and 3 lone pairs are repelling

Answer 26

linear

Question 27

Name the shape of the molecule when 6 atoms are repelling equally; include the angle of the bond

Answer 27

octahedral, 90

Question 28

Name the shape of the molecule when 5 atoms and 1 lone pair are repelling

Answer 28

square pyramidal

Question 29

Name the shape of the molecule when 4 atoms and 2 lone pairs are repelling and the bond angle

Answer 29

square planar, 90

Question 30

Name the shape of the molecule when 3 atoms and 3 lone pairs are repelling

Answer 30

T-shaped

Question 31

Name the shape of the molecule when 2 atoms and 4 lone pairs are repelling

Answer 31

linear