C15 - Using our Resources

Question 1

word equation

rusting

Answer 1

iron + oxygen + water → hydrated iron oxide

Question 2

define

corrosion

Answer 2

destruction of materials by chemical reactions with substances in the environment

Question 3

describe:

showing rusting

RP

Answer 3

In test tube, iron nail, stopper:
1. water + oxygen = rust
2. boiled water + oil = no rust
3. drying agent = no rust

Question 4

list 3

barrier methods to prevent iron rusting

Answer 4

1. painting
2. oil
3. electrolysis - cover with thin layer of other metal

Question 5

define:

sacrifical protection method

Answer 5

using another more reactive metal to prevent iron from rusting

Question 6

name and describe:

a sacrifical protection method

Answer 6

galvanising - coating iron with a layer of zinc

Question 7

name:

elements in alloys:
1. bronze
2. brass
3. gold (jewelry)
4. steel
5. stainless steel

Answer 7

1. copper, tin
2. copper, zinc
3. gold, silver, copper, zinc
4. iron, carbon
5. iron, chromium, nickel

Question 8

name:

2 properties of:
1. low carbon steel
2. high carbon steel
3. stainless steel

Answer 8

1. soft + malleable
2. strong + brittle
3. hard + corrosion resistant

Question 9

name:

1 use of:
1. low carbon steel
2. high carbon steel
3. stainless steel

Answer 9

1. car body
2. drill bits
3. cutlery

Question 10

word equation:

Haber Process

Answer 10

nitrogen + hydrogen ⇌ ammonia

Question 11

name:

sources of hydrogen and nitrogen

in the Haber Process

Answer 11

N₂ - air
H₂ - methane (CH₄)

Question 12

describe:

Haber Process

Answer 12

1. H₂ and N₂ into reactor
2. conditions: 200 atmospheres, 450°C, iron catalyst
3. passed into a cooling tank to make liquid ammonia
4. unreacted H₂ and N₂ are recycled

Question 13

chemical formula:

ammonia

Answer 13

NH₃

Question 14

define:

acronym NPK

Answer 14

Nitrogen, Phosphorus, Potassium

Question 15

How do plants use each substance in NPK fertilisers?

Answer 15

N: amino acids - proteins - growth
P: phosphates - DNA
K: enzymes - respiration + photosynthesis

Question 16

name:

the acid that ammonia can be converted into

Answer 16

nitric acid

Question 17

list:

3 word equations for different ammonium salts

Answer 17

• ammonia + nitric acid → ammonium nitrate
• ammonia + phosphoric acid → ammonium phosphate
• ammonia + sulfuric acid → ammonium sulfate

Question 18

formula:

ammonium ion

Answer 18

NH₄⁺

Question 19

name:

2 fertilisers from raw materials

Answer 19

• potassium chloride
• potassium sulfate

Question 20

name:

products of phosphate rock treated with nitric acid

Answer 20

calcium nitrate and phosphoric acid

Question 21

name:

products of phosphate rock treated with phosphoric acid

Answer 21

single superphosphate (calcium phosphate and calcium sulfate)

Question 22

name:

products of phosphate rock treated with sulfuric acid

Answer 22

triple superphosphate (calcium phosphate)

Question 23

define:

thermosoftening polymers

Answer 23

melt when heated

Question 24

define:

thermosetting polymers

Answer 24

do not melt when heated - they char and burn

Question 25

structural difference between thermosoftening and thermosetting polymers

Answer 25

thermosetting has cross-links, thermosoftening doesn't

Question 26

LDPE structure

Answer 26

polymers with branches, so arranged in a random order

Question 27

HDPE structure

Answer 27

less branches on polymers, so molecules line up closely

Question 28

# list 2: LDPE properties

Answer 28

- flexible - unreactive (corrosion resistance)

Question 29

# list 2: HDPE properties

Answer 29

- less flexible - high tensile strength - high chemical resistance - high impact resistance

Question 30

define composite

Answer 30

made from two or more materials with different properties

Question 31

Name the 2 parts of a composite material

Answer 31

- matrix - binds the other material together - reinforcement - materials that make up the bulk of the composite embedded in the matrix

Question 32

1 example of a composite and it’s make up

Answer 32

- wood - cellulose reinforcement in lignin matrix - reinforced concrete - steel reinforcement in concrete matrix