1.3: Bonding

Question 1

Describe ionic bonding

Answer 1

• occurs between a metal and a non-metal.
• electrons are transferred from metal to non-metal to achieve a full outer shell.

Question 2

What are the formulas of these common compound ions?
- sulfate
- hydroxide
- nitrate
- carbonate
- ammonium

Answer 2

• sulfate: SO4^2-
• hydroxide: OH^-
• Nitrate: NO3^-
• Carbonate: CO3^2-
• Ammonium: NH4^+

Question 3

Describe covalent bonding:

Answer 3

• two non-metals
• electrons are shared to achieve a full outer shell

Question 4

How do you portray ionic bonding?

Answer 4

• draw atoms-dots for one, crosses for the other- with an arrow from transferred electron to recipient atom
• arrow to both ions in square brackets with charges on top right corner, transferred electron drawn in same form on recipient ion (dots with crosses)

Question 5

How do you portray covalent bonding?

Answer 5

Dot and cross diagram

Question 6

Describe dative/coordinate bonding:

Answer 6

• dative bonds form when both of the electrons in the shared pair are supplied from a single atom.
• arrow from lone pair to recipient atom.

Question 7

How do dative bonds react compared to covalent bonds?

Answer 7

They react in exactly the same way

Question 8

Describe metallic bonding

Answer 8

• a lattice of positively charged ions surrounded by a sea of delocalised electrons
• electrostatic force of attraction between oppositely charged particles

Question 9

How do metal atoms characteristic affect their metallic bonding?

Answer 9

• larger ions have weaker forces of attraction due to their greater atomic radius
• the greater the charge on the positive ion (more valence electrons) the stronger the attractive forces

Question 10

What are the 4 different types of crystal structure?

Answer 10

• ionic (always giant)
• metallic
• simple molecular
• macromolecular

Question 11

What are the 3 main properties of ionic crystal structures and explain why they occur:

Answer 11

• high mp/bp electrostatic forces are strong, lots of energy to overcome
• conductive molten or in solution ions separate, no longer in lattice, free to carry a flow of charge
• brittle when layers of alternating charges are distorted, like chargesrepel, fragmenting the lattice

Question 12

Describe and explain the 3 main properties of metallic crystal structures:

Answer 12

• good conductors sea of delocalised electrons can move and carry a flow of charge
• malleable layers of positive ions can slide over eachother
  -high mp/solid at room temp very strong electrostatic forces of attraction between positive ions and valence electrons, lots of energy to overcome

Question 13

Describe and explain the 2 main properties of simple molecular structures:

Answer 13

• low mp/bp covalenty bonded and held together with weak van der waals forces
• poor conductors their structure contains no charged particles

Question 14

Describe and explain the properties of simple molecular structures:

Answer 14

• low mp/bp *covalenty bonded and held together with weak van der waals forces *
• poor conductors their structure contains no charged particles

Question 15

Describe and explain the properties of macromolecular structures:

Answer 15

• very high mpgiant covalent lattice structure, each atom has multiple covalents
• rigid strong covalent lattice- diamond

Question 16

How much do lone pairs affect the bond angles in a molecule?

Answer 16

Every lone pair the bond angle is reduced by 2.5 degrees.

Question 17

Name the shape and bond angle:
X-Y-X

Answer 17

• linear
• 180

Question 18

Name the shape,no. Lone pairs and bond angle:
Water

Answer 18

• V-shaped
• 104.5
• 2 lone pairs

Question 19

Name the shape and bond angle: 3 atoms no lone pairs

Answer 19

• trigonal planar
• 120*

Question 20

Name the shape and bond angle: 1 lone pair, 3 atoms

Answer 20

• triangular pyramid
• 107

Question 21

Name the shape and bond angle:
4 atoms, no lone pairs

Answer 21

• tetrahedral
• 109.5

Question 22

Name the shape and bond angle:
5 atoms, no lone pairs

Answer 22

• trigonal bipyramidal
• 90/120 (3 round middle, 1 too/bottom)

Question 23

Name the shape and bond angle:
6 atoms, no lone pairs

Answer 23

• octahedral
• 90

Question 24

Define electronegativity:

Answer 24

The power of an atom to attract a negative charge towards itself within a covalent bond

Question 25

How are permanent dipoles formed?

Answer 25

Two atoms bonded with different electronegativities, as the more electonegative draws electrons to itself

Question 26

What sort of lattice do permanent dipole molecules form?

Answer 26

- similar to an ionic lattice, d- to d+

Question 27

How are induced dipoles formed?

Answer 27

When electron orbits are influences by another charged particle- could be a permanent dipole etc

Question 28

Describe wander walls forces and its strength:

Answer 28

- induced dipole - weakest

Question 29

Describe a permanent dipole and its strength:

Answer 29

- asymmetrical (due to lone pairs) molecules form permanent dipoles- water explaination - medium strength

Question 30

Describe hydrogen bonding and its strength and properties:

Answer 30

- forms between hydrogen and the 3 most electronegative atoms: nitrogen, oxygen and fluorine - the lone pair on these atoms bond with another molecules hydrogen - strongest intermolecular force of attraction - higher mp/bp compared to similar sized molecules without it

Question 31

Name the shape and bond angle: 4 bonding pairs, 1 lone pair

Answer 31

- See saw shaped - 102

Question 32

Name the shape and bond angle: 3 binding pairs, two lone pairs

Answer 32

- T-shaped - 87.5

Question 33

Name the shape and bond angle: 5 bonding pairs, 1 lone pairs

Answer 33

- square pyramidal - 90

Question 34

Name the shape and bond angle: 4 bonding pairs, 2 lone pairs

Answer 34

- square planer - 90 - XeF4

Question 35

W