Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry > Ch15 Using our resources > Flashcards

Ch15 Using our resources Flashcards

1
Q

Corrosion

A

destruction of materials by chemical reactions with substances in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Rusting

A

corrosion of iron
oxygen and water are necessary for it to take place
iron + oxygen + water -> hydrated iron(III) oxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Preventing rust

A

coating the iron with a barrier:

grease/oil
plastic
electroplating
paint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Aluminium rusting

A

doesn’t happen

- has an aluminium oxide coating that protects the metal from corroding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Using a more reactive metal to prevent rusting

A

molten metal or electroplating
example- zinc is used to galvanise iron
zinc reacts with oxygen instead, losing electrons and becoming oxidised
sacrificial protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Copper alloys

A

Bronze -> copper + tin

Brass -> copper + zinc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Aluminium alloy properties

A

low density
lightweight but strong
- used to build aircraft
- used as armour plating on military vehicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bronze uses

A

toughness and resistance to corrosion
used for
- statues and decorative items
- ship propellers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Brass uses

A 
hard
can be hammered into shapes and pressed into intricate shapes
used for
- musical instruments
- door fittings and taps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Gold alloys

A

usually alloyed with copper, silver and zinc to make jewellery
proportion of gold in the alloy is measured in carats
24 carat being 100% pure gold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Steel

A

alloy of iron + carbon and other metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

low- carbon steels

A

removing carbon from the iron obtained from a blast surface
soft and easily shaped
used in machinery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

high-carbon steel

A

strong but brittle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

nickel-steel alloy

A

resistant to stretching forces

used for drill bits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

stainless steels

A

chromium + nickel
hard
resistant to corrosion
used for cooking utensils and reaction vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

thermosoftening polymers

A

soften easily and then re-set when they cool down
made up of individual polymer chains tangled together
easy to separate
weak intermolecular forces

17
Q

thermosetting polymers

A

don’t melt when heated
have strong covalent bonds forming ‘cross-links’ between polymer chains
rigid
don’t soften

18
Q

properties of polymers depend on…

A

monomers used to create it

conditions chosen to carry out the reaction

19
Q

low density poly(ethene)

A

made from ethene monomers
uses high pressure and a trace of oxygen
polymers are randomly branched and cannot pack closely together

20
Q

high density poly(ethene)

A 
made from ethene monomers
uses a catalyst at 50°C at a slightly raised pressure
straight chains
packed closer
higher softening temp 
stronger
21
Q

Soda- lime glass

A

made by heating a mixture of sand, limestone and sodium carbonate
random arrangement of particles

22
Q

Borosilicate glass

A

made from sand and boron trioxide
melts at high temperatures than soda-lime glass
used for ovenware

23
Q

Ceramics

A

made from shaping wet clay
- made from aluminium and potassium
- silicon and oxygen
heated in a furnace so the water evaporates and strong bonds form between layers

24
Q

Ceramic properties

A

brittle

  • sharp blow distorts layers in structure
  • ions with like charges repel each other, cracking the ceramic object
25
Q

composites

A

made of two materials

has improved properties

26
Q

reinforcement

A

a matrix(a binder) of one material surrounding and binding together fibres or fragments of the other material

27
Q

examples of composites

A

concrete

  • cement, sand and gravel mixed with water
  • very hard
  • strong in compression
  • can be set around matrix of steel rods

plywood
- thin sheets of wood glue together with successive layers of grain at right angles

28
Q

Haber process

A
  • nitrogen in the air
  • hydrogen from methane
  1. gases are purified
  2. passed over an iron catalyst at high temp(450°C) and high pressure(200 atmospheres)
  3. some hydrogen and ammonia react to form ammonia
    N2 + 3H2 -> 2NH3
  4. ammonia is then removed- cooling the gases so the ammonia liquifies and is then separated from the unreacted N and H gas which have higher bp
  5. unreacted hydrogen and nitrogen are recycled back into the reaction mixture
29
Q

Haber reversible reaction

A

ammonia gas breaks down into hydrogen and nitrogen

30
Q

NPK fertilisers

A

plants need nitrogen to grow(make proteins)
- have to use Haber process to change nitrogen gas into ammonia because plants can only absorb soluble form
phosphorous
potassium

31
Q

making hydrogen for Haber process

A

methane + steam -> hydrogen + carbon monoxide

at very high temp

32
Q

making nitrogen for Haber process

A

fractional distillation of liquid air (cooled to -200°C)

33
Q

Economics of Haber process

A

energy cost to liquefy and compress air
costs for heating water
methane gas is expensive

34
Q

maximum yield of ammonia

A

make pressure high as possible to shift
(volume of reactants > vol of products)

decreasing temp
-slower rate of reaction(expensive)

iron catalyst

35
Q

phosphorous treated with nitric acid

A

produces phosphoric acid and calcium nitrate

phosphoric acid is then neutralised with ammonia to produce ammonium phosphate

36
Q

phosphorous treated with sulfuric acid

A

produces superphosphate

- mixture of calcium phosphate and calcium sulfate

37
Q

phosphorous rock treated with phosphoric acid

A

produces triple superphosphate

- calcium phosphate

38
Q

sources of potassium

A

potassium sulfate and potassium chloride mined from the ground

39
Q

fertilisers

A
  1. ammonia + phosphoric acid -> ammonium phosphate
  2. ammonia + sulfuric acid -> ammonia sulfate
  3. ammonia + nitric acid -> ammonium nitrate

Chemistry (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions