Chemistry

Question 1

Melting point: Simple covalent

Answer 1

Low

Question 2

Melting point: giant covalent

Answer 2

High

Question 3

Melting point: metallic

Answer 3

High

Question 4

Melting point: giant covalent

Answer 4

High

Question 5

Types of bonding

Answer 5

Giant ionic
Giant covalent
Simple covalent
Metallic

Question 6

Why are melting points high in giant ionic, giant covalent and metallic?

Answer 6

Strong electrostatic force of attraction

Question 7

Why are melting points low in simple covalent?

Answer 7

Weak intermolecular forces of attraction.

Question 8

Why are intermolecular forces so easy to break?

Answer 8

They don’t require much energy to break.

Question 9

Why can simple ionic compounds conduct when molten but not solid?

Answer 9

When solid, ionic compounds have their ions in fixed positions and so cannot carry charge. when molten, ionic compounds have their ions free to move and carry charge.

Question 10

Why can metals conduct?

Answer 10

They have free delocalised electrons, able to move around the structure and carry charge.

Question 11

Why is chlorine a gas at room temperature, but sodium chloride is not?

Answer 11

Chlorine is a gas as it has covalent bonding, meaning it has a low melting and boiling point with simple molecules. Sodium chloride is a solid at room temperature as it has ionic bonding, strong bonds, expands in all directions (lattice), large amounts of energy are needed to break bonds.

Question 12

Why may an experiment be innacurate?

Answer 12

Solution may have been improperly stirred,
Concentrations may be differet,
Sample sizes may be inaccurate.

Question 13

Graphite is soft, why?

Answer 13

Layers can Slide Over each other because there are no covalent bonds between layers

Question 14

Diamond is hard, why?

Answer 14

It has four covalent bonds between the atoms and covalent bonds are strong.

Question 15

Graphite conducts, why?

Answer 15

Graphite has delocalised electrons which can move throughout the whole structure.

Question 16

Why are diamonds used in cutting bits?

Answer 16

They are hard (you may loose marks for strong)

Question 17

Why are balls a bad way to show crystals

Answer 17

They are not in 3D
Particles should be different sizes

Question 18

What kind of metal forms a coloured metal?

Answer 18

Transition metals

Question 19

Atoms vs Ions

Answer 19

Atoms are nuteral, ions have a charge.

Question 20

ionic compounds -ide vs -ate

Answer 20

Ide means the ionic compound is comprised of two or more elements, ate means it has three or more

Question 21

Ionic lattice structure

Answer 21

Ionic lattices are regular repeating patterns of oppositely charged atomic ions

Question 22

How are ions held together?

Answer 22

Ionic lattices are held together by the electrostatic force of attraction between positive and negative ions

Question 23

Why do ionic compounds have high melting points?

Answer 23

Ionic compounds have high melting points as it requires a lot of energy to break the electrostatic forces of attraction between molecules

Question 24

Why do covalent bonded compounds melt and boil at low temperatures?

Answer 24

Weak intermolecular forces between molecules

Question 25

Why do covalent substances not transmit electricity well?

Answer 25

Covalent substances have no free electrons to transmit energy

Question 26

Why do we use diamonds? What do we use them in?

Answer 26

Diamonds are hard, we use them in blade edges, drills, jewellery.

Question 27

Limitations if the dot and cross representation of bonding

Answer 27

Doesn’t illustrate the relative sizes of the atoms and fails to illustrate the 3D aspect of atoms.

Question 28

Weak Acids:

Answer 28

They do not fully ionise

Question 29

Strong Acids:

Answer 29

Fully ionise

Question 30

Acids with Carbonates:

Answer 30

Produces A salt, water and carbon dioxide.

Question 31

Acids + Metals

Answer 31

Salt + Hydrogen

Question 32

Acids ions:

Answer 32

H+ Ions

Question 33

Detecting Acids:

Answer 33

Litmus: Red Methyl Orange: Red Phenolphthalein: Clear

Question 34

What is relative formula mass?

Answer 34

Relative formula mass is the mass of all atoms in a substance.

Question 35

Ions

Answer 35

Charged atoms

Question 36

Cations

Answer 36

Positively charged

Question 37

Anions

Answer 37

Negatively charged

Question 38

Anions form from:

Answer 38

Non metals

Question 39

Cations form from:

Answer 39

Hydrogen or metals

Question 40

Covalent bonds

Answer 40

A shared pair of electrons

Question 41

Properties of covalent bonds:

Answer 41

Strong electrostatic forces Form with metals and non metals Produce molecules Group number is number or bonds

Question 42

Strong covalent.

Answer 42

Low melting + boiling points Non metals Do not conduct as they are not charged with no free electrons. Strong

Question 43

Giant molecular

Answer 43

Many covalent atoms in regular repeating lattice Non metal, compounds, high melting + boiling points Solid at room temperature. Diamond, graphite

Question 44

What’s special about graphite?

Answer 44

Each atom bonded to three other carbon atoms, they are layers that connect with weak intermolecular forces, strong covalent bonds between atoms in layer. Regular lattice.

Question 45

Metallic bonding

Answer 45

Shiny, conductors, dense, high melting point. Giant lattice of positively charged metal ions in sea of electrons. Malleable.

Question 46

What is metal reactivity?

Answer 46

The reactivity of a metal is linked to how easy it is for a metal to form its positive ion.

Question 47

What is the use of a fullerene

Answer 47

Lubricant

Question 48

Single bond

Answer 48

Two atoms share one pair of electrons

Question 49

Double bond

Answer 49

Two atoms with four electrons bonding