Reactivity Series And Redoz

Question 1

What are easiest metals to extract

Answer 1

The least reactive metals like gold beacsue they can be found as native metals and occur naturally as their metal

Question 2

How do you extract moderately reactive metals

Answer 2

Metals below carbon can be extracted cheaply and easily by heating their ores with carbon to bring about a displacement reaction. These metals are not found native because they combine with oxygen or moisture in the air to from compounds

Question 3

How do you extract metals more reactive than carbon

Answer 3

By electrolysis

Question 4

What are the three raw materials fed into the top of the blast furnace

Answer 4

Iron ore , coke , limestone and blast of hot air

Question 5

What does the coke do

Answer 5

Burnis in hot air to form carbon dioxidE. This reaction is very exothermic and provides the high temperatures needed for the furnace to function . Higher up in the furnace carbon dioxide reacts with more coke to form carbon monoxide

Question 6

What does the carbon monoxide do

Answer 6

Reacts with iron oxide ( haematite) to form carbon dioxide and molten iron which collects at the base of the furnace where it can be tapped off .

Question 7

What does the calcium carbonate do

Answer 7

Thermally decomposes to form calcium oxide and carbon dioxide . Calcium oxide reacts with silicon dioxide impurities to make calcium silicate which forms slag that floats on top of the molten iron and can be tapped off seperately and used for road surfacing and cement making

Question 8

How is steel made

Answer 8

Most of carbon is removed from the pig iron making it stronger than cast iron and it’s used for construction . This is done by basic oxygen process , oxygen gas is bubbled through molten pig iron making most of the carbon present burn off as carbon dioxide gas leaving mild steel . Calcium oxide is also added to take away impurities . Other metals can be addressed to make stainless steel which is very resistant to corrosion so is therefore used for cutlery

Question 9

Cast iron

Answer 9

Iron from the blast furnace impure , very hard but brittle used for guttering . Wrought iron is pure iron and used for decoration

Question 10

High carbon steel

Answer 10

Makes steel harder but more brittle so used for cutting tools

Question 11

Reduction

Answer 11

Gain of electrons loss of oxygen

Question 12

Oxidation

Answer 12

Gain of oxygen loss of electrons

Question 13

Why aluminium dissolved in cryolite

Answer 13

Needs to be molten to conduct electricity , cryolite has a lower melting point than aluminium making electrolysis cheaper and easier

Question 14

What is the cathode for electrolysis of aluminium

Answer 14

Graphite lining of electrolysis cell . Molten aluminium sinks to bottom of cell on cathode and can be talked off

Question 15

What are the anodes for electrolysis of aluminium

Answer 15

Graphite anodes dipped into electrolyte . Oxygen glass forms here and is hot so it causes the electrodes to burn away making it expensive as they have to be replaced

Question 16

How do you extract zinc

Answer 16

Roast zinc sulphide in air to give zinc oxide
- React it with sulphuric oxide to give zinc sulphate then electrolyse using l ad anode and aluminium cathode
Or - thermal extraction mic zinc oxide with coke and displace lent reaction will occur forming carbon monoxide zinc
Carbon monoxide removes oxygen from zinc oxide to give zinc and carbon dioxide

Question 17

What is nickel

Answer 17

Corrosion resistant

Question 18

What is rusting

Answer 18

Redox reaction , iron atoms in the metal loose electrons to form iron 3 ions in the rust iron oxide. The oxygen with it reacts is reduced and gains these electrons

Question 19

How do you prevent rusting

Answer 19

1. Barriers e.g. Painting
   2.alloying this iron
2. Use sacrificial metals , galvanised iron is iron coated with a layer of zinc which is more reactive than iron so it corrodes instead of the iron
   Zinc looses electrons to from zinc ions

Question 20

Reactivity series

Answer 20

Postassium sodium lithium calcium magnésium aluminium carbon zinc iron hydrogen copper

Question 21

What colour does iron turn when oxidised

Answer 21

Colourless to yellow

Question 22

Colour change iodide

Answer 22

Colourless to brown

Question 23

Colour change bromine

Answer 23

Colourless to orange

Question 24

Rust chemichal name

Answer 24

Hydrated iron oxide

Question 25

What happens when sulphur is heated

Answer 25

Melts then ignites biting with a blue flame forming sulphur dioxide

Question 26

What is air mainly

Answer 26

Nitrogen and oxygen (1/5)

Question 27

How do show how much I uber is in air

Answer 27

Push 100cm3 of air backwards and forwards over heated cooled which will go black as copper oxide is formed .eventualky all oxygen in air will be used and reaction will stop leaving 79cm3 in the gas syringe

Question 28

How is oxygen made in the lab

Answer 28

Hydrogen peroxide solution using manganèse oxide as the catalyst

Question 29

How do you make carbon dioxide

Answer 29

Dilute hydrochloride acid and and calcium carbonate in marble chips

Question 30

What happens with magnesium and steam

Answer 30

Magnésium burns with a bright white flame producing hydrogen that is ignited at the end of the delivery tube . Metals below hydrogen don’t react with stems

Question 31

How do you take pure salt from rock salt

Answer 31

Crush rock salt and mix it with hot water , the salt will dissolve and the impurities won’t do the impurities can be filtered off

Question 32

How do you make pure water from sea water

Answer 32

Water boils and is condensed into liquid by a condenser whereas salt from sea water remains in te flask

Question 33

What is recrystallisation used for

Answer 33

Purify substances contaminated with small quantities of other soluble substances , dissolve impure solid in hot water ,and then allow to cool impurities will stay in solution and crystals can be filtered

Question 34

What is paper chromatography

Answer 34

Spot of ink put on chromatography paper and hung in a boiling tube containing some solvent , solvent soaks up into the paper and the sealed tube stops it from evaporating . Dyes that make up the ink will differ in how strongly they stick to the paper and how soluble they are in the solvent .