Bonding And Substances

Question 1

What is an ionic bond

Answer 1

A bond between a metal and non-metal involving the transfer of electrons.

Question 2

What types of ions do elements in group 1 and 2 form?

Answer 2

Cations
Groups 1 metals will form 1+
Group 2 metals will form 2+

Question 3

What type of ions do elements in the groups 6 and 7 form

Answer 3

Anions (negative)
Group 6 will form 2- ions
Group 7 will form 1- ions

Question 4

What does it mean if an ionic compound ends in -ide

Answer 4

The compound contains 2 elements

Question 5

What does it mean if an ionic compound ends in -ate?

Answer 5

The compound contains at least 3 elements, one of which is oxygen

Question 6

Describe the structure of an ionic compound

Answer 6

Lattice structure
Regular arrangement of ions
Ions held together by strong electrostatic forced between ions with opposite charges.

Question 7

What is a covalent bond?

Answer 7

A bond formed when an electron pair is sharer between two atoms.

Question 8

What forms as a result of covalent bonding

Answer 8

A molecule

Question 9

Draw a dot and cross diagram for formation of Methane (CH4)

Answer 9

Question 10

Why do ionic compound have high melting points?

Answer 10

Strong electrostatic attraction between the positive and negative ions requires a lot of energy to overcome.

Question 11

When do ionic compound conduct electricity? Why?

Answer 11

When molten or aqueous because ions are charged particles and are now free to move. When solid, ions can’t move.

Question 12

Why do simple molecular compounds have low melting and boiling points?

Answer 12

They have weak intermolecular forces which only require a little energy to overcome.

Question 13

Do simple molecular compounds conduct electricity?

Answer 13

No, there’s no charged particles.

Question 14

Do giant covalent structures have a High melting point?

Answer 14

Yes, because they have lots of strong covalent bond which require a lot of energy break.

Question 15

How do metals conduct electricity and heat?

Answer 15

The positive ions are fixed in a sea of delocalised electrons. These electrons are free to move and carry charge/energy.

Question 16

Metals are insoluble in water. True or false?

Answer 16

True

Question 17

Name two giant covalent structure formed from carbons atoms

Answer 17

Graphite

Diamond

Question 18

Describe structure of graphite

Answer 18

Each carbon atom bonded to 3 other carbon atoms
Layers of hexagonal rings of carbon atoms
Weak intermolecular forces between layers
One delocalised electron per carbon atom

Question 19

Describe and explained the properties of graphite

Answer 19

Graphite is soft/slippery because there are only weak intermolecular forces between layers which allow the layers to Slide Over one another.

Graphite conducts electricity because there is one delocalised electron per carbon atom. Delocalised electors are mobile charges.

Question 20

Describe structure of diamond

Answer 20

All carbon atoms are covalently bonded to four other carbon atoms
No delocalised electrons

Question 21

Describe the properties of diamond

Answer 21

Very hard
Very high melting point
Doesn’t conduct electricity as there are no charged particles

Question 22

What are uses of graphite? Why?

Answer 22

Electrodes because graphite conducts electricity and has high melting point
Lubricant because it’s slippery (the layers in graphite can Slide Over each other)

Question 23

Why is diamond used in cutting tools?

Answer 23

It’s very hard

Question 24

What is a fullerene?

Answer 24

A molecule made of carbon, shaped like a closed tube or hollow ball.

Question 25

Name two fullerenes

Answer 25

Graphene

C60 (Buckminsterfullerene)

Question 26

What are properties of C60

Answer 26

Slippery due to weak intermolecular forces
Low melting point
Spherical
Strong covalent bonds between carbon atoms in a molecule
Large surface area

Question 27

What are properties of graphene?

Answer 27

High melting point due to covalent bonding between carbon atoms
Conducts electricity because it has delocalised electrons

Question 28

Why is graphene useful in electronics?

Answer 28

It is extremely strong and has delocalised electrons which are free to move and carry charge.
It is only one atom thick as it is single layer of graphite.

Question 29

What is a polymer?

Answer 29

Long chain molecules formed form many monomers

Question 30

Draw the structure of poly(ethene)

Answer 30

Question 31

What bond is formed Between carbon atoms in polymer molecules

Answer 31

Covalent bonds

Question 32

Properties of metals?

Answer 32

High melting point 
High density 
Good conductors of electricity 
Malleable and ductile 
Shiny

Question 33

Why can metals conducts electricity?

Answer 33

The electrons in the metals are charges that can move.

Question 34

Properties of non-metals

Answer 34

Low boiling points
Poor conductors
Brittle when solid

Question 35

Limitations of: Dot and cross, 2D diagrams and 3D diagrams (in ionic compounds)

Answer 35

Dot and cross - no lattice structure or ionic bonds
2D - only shows one layer, doesn’t shown formation of ions
3D - doesn’t show charged, shows spaces between ions

Question 36

Limitation of: dot & cross + ball & stick diagrams (in covalent molecules)

Answer 36

Dot and cross - doesn’t show the relative sizes of atoms or intermolecular forces
Ball and Stick - bonds shown as sticks rather than forces, doesn’t show how covalent bonds form.

Question 37

Describe an experiment to work out empirical formula of magnesium oxide

Answer 37

Question 38

Equation that links mass, moles and Mr together

Answer 38

Mass = moles x mr

Question 39

What is avogadro constant?

Answer 39

The number of atoms, molecules or ions in one mole of a given substance
6.02 x 10^23