Creation Of New Substances

Question 0

Electrolyte

Answer 0

Substance electrolysed

Question 1

Electrolysis

Answer 1

Ionic compounds do not conduct electricity when solid because the ions are not free to move

Ionic compounds conduct electricity when molten or in an aqueous solution

Electrolysis is the decomposition of a substance by passing an electric current through it

Question 2

Anode (electrolysis)

Answer 2

Positive electrode
Non-metal formed here (due to negative ions)
Non-metal loses electrons

Question 3

Cathode (electrolysis)

Answer 3

Negative electrode
Metal is formed here, due to positive ions
Metal gains electrons

Question 4

Electrolysis of aqueous solutions

Answer 4

A aqueous solution containing ions can be electrolysed

Water has an influence on the reaction

Question 5

Negative electrode

Answer 5

Cathode

Hydrogen or a metal formed

Question 6

Positive electrode

Answer 6

Anode

Oxygen or a non-metal formed

Question 7

Metal more reactive than hydrogen

Answer 7

Hydrogen at cathode

Question 8

Metal less reactive than hydrogen

Answer 8

Metal at cathode

Question 9

Condensation reactions

Answer 9

Two molecules react -> form a larger molecule with the elimination of a small molecule (water)

Question 10

Condensation polymers

Answer 10

Many monomers join together to make a polymer for each pair of monomers that join a small molecule is eliminated (water)

Polyesters (herylene)
Polyamides (nylon)

Question 11

Disposing of polymers- landfill

Answer 11

Uses up valuable land, non-biodegradable

Question 12

Disposing of polymers- incineration

Answer 12

They release alot of energy when burnt (useful)

Carbon dioxide produced as well as toxic gases

Question 13

Disposing of polymers- recycling

Answer 13

Reduces disposal problems

The separation of different polymers is expensive and difficult

Question 14

Addition polymers

Answer 14

A long- chain molecule formed by many small monomers joined together

Have a c-c double bond, this breaks allowing monomers to attach together

Question 15

Burning fuel in cars

Answer 15

High temperatures means nitrogen + oxygen -> oxides of nitrogen

They dissolve in the air to form acid rain

Question 16

Incomplete combustion

Answer 16

Lack of oxygen

Produces carbon monoxide

Question 17

Catalytic converters

Answer 17

Carbon monoxide -> carbon dioxide

Oxides of nitrogen -> nitrogen and oxygen

Question 18

Cracking

Answer 18

Long-chained hydrocarbons (alkanes) passed over a catalyst
(Silica or aluminium oxide) at 600-700*C

Many short-chained alkanes produced, at least one alkene

Question 19

Problems of fractions

Answer 19

Far too many higher boiling point fractions

Not enough of the lower boiling point fractions

Cracking: converting long-chained hydrocarbons -> shorter-chained ones
To make more gasoline

Question 20

Refinery gas uses

Answer 20

Bottles gas

Question 21

Gasoline uses

Answer 21

Petrol for cars

Question 22

Kerosene uses

Answer 22

Fuel for aeroplanes
Central heating boilers
Paraffin small heaters

Question 23

Diesel oil uses

Answer 23

Diesel fuel for: buses, lorries, trains, cars

Question 24

Fuel oil uses

Answer 24

Fuel for ships, industrial heating

Question 25

Bitumen uses

Answer 25

Road surfaces, covering flat roofs

Question 26

Factions of crude oil

Answer 26

``` Refinery gases Gasoline Kerosene Diesel oil Fuel oil Bitumen ```

Question 27

Refining of crude oil

Answer 27

Crude oil heated until it is a vapour Fed into the column at the bottom Hydrocarbons with very high boiling points immediately turn to liquids and are tapped off at the bottom of the column The other hydrocarbons rise up the column As they rise they cool down They will condense at different heights Refinery gasses stay S gases and come out of the top of the column

Question 28

Crude oil

Answer 28

A mixture of hydrocarbons mainly alkanes Must be refined before having any use First step is fractional distillation Carried out in a fractionating column 400*C at bottom 40*C at top

Question 29

aluminium characteristics

Answer 29

High strength to weight ratio Good conductor of heat and electricity Non-toxic Resists corrosion

Question 30

Uses of aluminium

Answer 30

``` Aeroplane bodies Overhead power cables Saucepans Food cans Window frames ```

Question 31

Iron characteristics

Answer 31

Strong | Withstands collisions

Question 32

Uses of iron

Answer 32

Car bodies Iron nails Ships Bridges

Question 33

Extraction of iron

Answer 33

Raw materials- iron ore, coke, limestone, air (mixed added at top) Oxygen + coke ---> carbon dioxide Carbon dioxide + coke ---> carbon monoxide Carbon monoxide reduces iron (iii) oxide in iron ore Iron melts, collects at bottom, tapped off Calcium carbonate in limestone decomposes ---> calcium oxide Calcium oxide + silicon dioxide (impurity) ---> calcium silicate Calcium silicate melts, collects as molten slag, tapped off

Question 34

Electrolysis of aluminium

Answer 34

Aluminium melts and collects at the bottom,tapped off Some oxygen produced at positive electrode Reacts with the graphite ----> carbon dioxide gas Positive electrode must be replaced after burning away

Question 35

Extraction of aluminium electrodes

Answer 35

Graphite (carbon)

Question 36

Extraction of aluminium Electrolyte

Answer 36

Solution of aluminuim oxide dissolved in molten cryolite

Question 37

Main ore of aluminium

Answer 37

Bauxite -> must first be purified before producing aluminium oxide

Question 38

Aluminium oxide

Answer 38

High melting point | Must be dissolved in molten cryolite

Question 39

Ore

Answer 39

Rocks with enough metal worth mining for

Question 40

Unreactive metals in ores

Answer 40

Occur as elements

Question 41

Ractive metals in ores

Answer 41

Found as compounds from which they must be extracted

Question 42

Reactive metals

Answer 42

Electrolysis of the molten chloride/oxide Most powerful method but very expensive

Question 43

Medium/ lower reactivity metals

Answer 43

Heat with a reducing agent (carbon/carbon monoxide)

Question 44

Gold/ silver -unreative

Answer 44

Occur naturally as the elements