CHEMISTRY

Question 1

what happens in electrolysis?

Answer 1

requires a liquid to conduct electricity

Positive ions move towards negative electrodes

Question 2

what does electrolysis extract? and what does it do and what is required?

Answer 2

metals more reactive than carbon.
makes it pure
high temperature & energy

Question 3

what are the advantages of quarrying?

Answer 3

• used as building materials
• limestone products from thermal decomposition used to neutralise soils
• used in power station chimneys to neutralise sulphur dioxide

Question 4

what are the disadvantages of quarrying?

Answer 4

• permanently changes the landscape

- noise and dust pollution

Question 5

what other 2 methods could we use to extract small bits of copper?

Answer 5

low grade ores - bioleaching and phytomining

Question 6

how does bioleaching work?

Answer 6

bacteria gets energy from bond between copper and sulfur separating out the copper. Leachate is produced containing copper and extracted by filtering

Question 7

how does phytomining work?

Answer 7

low grade ore
grow plants in soil containing copper, builds up in leaves, plants harvested and burnt in a furnace, copper collected from ash.

Question 8

where is crude oil from?

Answer 8

buried remains of plants and animals

Question 9

advantages of crude oil?

Answer 9

good fuels for transport
reliable
cheap

Question 10

what are the disadvantages of crude oil?

Answer 10

non-renewable
oil spills- birds poisoned
causes global warming and acid rain

Question 11

what are 3 alternatives fuels for crude oil?

Answer 11

ethanol
biodiesel
hydrogen gas

Question 12

how is ethanol produced?

Answer 12

produced from plant material made by the fermentation of plants

Question 13

what are the pros of the alternative fuel of ethanol?

Answer 13

carbon neutral and it’s only other product is water - no pollution

Question 14

what are the cons of ethanol fuel?

Answer 14

engines need to be converted and isn’t widely available

Question 15

how is the alternative fuel biodiesel produced?

Answer 15

by vegetable oils & rapseed oils

Question 16

what are the pros and cons of biodiesel?

Answer 16

carbon neutral, produces less sulphur dioxide & engines don’t need to be converted

expensive

Question 17

how is hydrogen gas produced?

Answer 17

electrolysis of water

Question 18

what are the pros of hydrogen gas?

Answer 18

very clean only forms water

need special expensive equipment & isn’t widely available

Question 19

what is cracking?

Answer 19

long chain molecules like diesel into short chain molecules like petrol paraffin and ethene

Question 20

what type of reaction is cracking?

Answer 20

thermal decomposition

Question 21

what are the conditions needed for cracking? what are the products?

Answer 21

high temperature to vaporise it then passed over a catalyst. produces alkenes

Question 22

what is polymerisation?

Answer 22

joining lots of alkenes together

Question 23

how do you convert ethene to ethanol? pros, cons?

Answer 23

hydrated with steam in presence of a catalyst.
cheap
ethene is produced from a non renewable resource

Question 24

how else could you get ethanol but from renewable resources?

Answer 24

fermentation - sugar (from plants) = carbon dioxide + ethanol

Question 25

how do you get oils from plants?

Answer 25

plant material is crushed, then you press the crushed plant and squash the oil out.

Question 26

what are the uses of extracting oils from plants?

Answer 26

provides humans energy, high boiling point than water - cook foods faster, rapeseed oil turned into biodiesel

Question 27

why would you use the method hydrogenating on oils?

Answer 27

most are runny at room temperature - not useful

Question 28

how is the process of hardening: hydrogenating done?

Answer 28

reacted with hydrogen in the presence of a nickel catalyst at 60c - makes them saturated

Question 29

what 3 things does recycling metals do?

Answer 29

saves energy saves natural resources less pollution

Question 30

what type of fats are less healthy?

Answer 30

saturated

Question 31

what uses do polymers have?

Answer 31

plastic bags | memory foams for beds - smart polymers

Question 32

what are the pros and cons of polymers?

Answer 32

cheap nonbiogradable, from crude oil and its non-renewable so prices will rise.

Question 33

what are the transition metals

Answer 33

ones in the middles

Question 34

what are the symbols for calcium hydroxide?

Answer 34

Ca(OH)2

Question 35

how is calcium hydroxide formed?

Answer 35

adding water to calcium oxide

Question 36

why might iron be converted to steel?

Answer 36

iron is brittle | steel is strong / flexible

Question 37

what is limestone heated in?

Answer 37

rotary lime kiln

Question 38

what products are formed from adding water and sand to limestone?

Answer 38

cement or mortar

Question 39

if you then add crushed rocks?

Answer 39

concrete

Question 40

metals unreactive are found in their?

Answer 40

native state, most are found as metal ores and need to extracted

Question 41

what is alloying?

Answer 41

adding small amounts to other elements - can improve properties as now has a irregular structure

Question 42

what is crude oil a mixture of?

Answer 42

hydrogen and carbon

Question 43

gases in the air can?

Answer 43

be separated from | fractional distillation for use in industry.

Question 44

what does the earths atmosphere consist of?

Answer 44

nitrogen 80% oxygen 20% co2 0.037% other gases 0.9%

Question 45

in a emulsifier is the tail hydrophilic? what is it attracted to?

Answer 45

YES | attracted to WATER

Question 46

name the order of the alkenes?

Answer 46

methane - CH4 Ethane propane butane

Question 47

what properties does a shorter molecule have?

Answer 47

the less viscous it is - more runny more volatile - turn into gas at lower temperature more flammable

Question 48

what is complete combustion

Answer 48

all the fuels burn

Question 49

what is formed from partial combustion

Answer 49

solid particulates of soot & carbon monoxide

Question 50

what causes global dimming

Answer 50

soot & ash - reflect sunlight back

Question 51

what do you get when you add a LOT of water to slaked calcium hydroxide?

Answer 51

calcium hydroxide solution - limewater

Question 52

what can limewater be tested for?

Answer 52

carbon dioxide- if it's present so is limestone - bringing it back to the start of the calcium carbonate

Question 53

what is the core of earth made out of?

Answer 53

iron and nickel

Question 54

what was in the earths early atmosphere?

Answer 54

volcanoes added lots of c02 water and nitrogen cooled and condensed into the oceans plants appeared and photosynthesised to absorb the c02 and release oxygen

Question 55

how would you test for an unsaturated hydrocarbon?

Answer 55

add bromine water, will turn from orange to colourless

Question 56

what makes unsaturated hydrocarbons?

Answer 56

cracking

Question 57

what makes saturated hydrocarbons?

Answer 57

crude oil from fractional distillation

Question 58

when metal carbonates react with acids what is formed?

Answer 58

salt water and carbon dioxide

Question 59

how is iron removed from its ore?

Answer 59

mix iron oxide and carbon in a blast furnace- reduction of carbon carbon displaces the iron because it's more reactive we so this because iron oxide is originally in the ore

Question 60

what is titanium used for?

Answer 60

medical implants | strong but not corrosive

Question 61

what is the equation for complete combustion?

Answer 61

hydrocarbon + oxygen = carbon dioxide + water ALWAYS MAKES THAT

Question 62

what is the equation for incomplete combustion?

Answer 62

hydrocarbon + 1.5oxygen = carbon monoxide + water

Question 63

are alkenes saturated?

Answer 63

NO

Question 64

which are the most useful hydrocarbons?

Answer 64

short chain molecules - why cracking is done

Question 65

monomers are always?

Answer 65

alkenes