Limestone and Metal

Question 1

What does limestone mainly consist of?

Answer 1

Calcium carbonate

Question 2

What is the symbol equation for calcium carbonate?

Answer 2

CaCO3

Question 3

What are the products produced when calcium carbonate is heated?

Answer 3

Calcium oxide and carbon dioxide
CaO CO2
also known as Quick lime

Question 4

What are the products produced when calcium carbonate reacts with an acid?

Answer 4

a salt, water and carbon dioxide

Question 5

What substance forms when you add water to calcium oxide?

Answer 5

calcium hydroxide (CaOH)2

Question 6

How can we test for carbon dioxide in a gas?

Answer 6

Make a solution calcium hydroxide in water (also known as lime water) and bubble gas through it, the solution will turn cloudy if carbon dioxide is in the gas. This cloudiness is caused by the formation of calcium carbonate.

Question 7

How do we make cement?

Answer 7

powdered limestone is heated in a kiln with clay.

Question 8

How do we make mortar?

Answer 8

By adding sand and water to cement.

Question 9

How do we make concrete?

Answer 9

By adding sand and aggregate to cement.

Question 10

What are the advantages and disadvantages of quarrying limestone?

Answer 10

ADV-
Limestone provides thing that people want- houses, roads, chemicals used in making dyes, paints and medicines/
Can neutralise acidic soil.
provides jobs for local people
Brings in money to the local economy.
After quarrying landscaping and restoration takes place.

DISADV- 
Noise
Dust
Destroys habitats
ruins landscape

Question 11

what are the pros of limestone as a building material?

Answer 11

PROS
Widely available
Cheaper than granite or marble
Easy to cut 
looks attractive
hard wearing
doesn't rot 
fire-resistant

Question 12

What are the pros and cons of concrete as a building material?

Answer 12

PROS
Can be poured into moulds
very quick
cheap 
doesn't rot
doesn't corrode 

CONS
Low tensile strength- can crack
unattractive

Question 13

What is a metal ore?

Answer 13

a rock containing enough metal to make it worthwhile extracting.

Question 14

How are metals below carbon in the reactivity series extracted from their ores, and why?

Answer 14

Reduction with carbon because carbon can only take the oxygen away from metals that are less reactive then carbon itself is.

Question 15

How are metals above carbon in the reactivity series extracted?

Answer 15

Electrolysis, uses more energy, more expensibe

Question 16

What is smelting?

Answer 16

when an ore is heated in a furnace.

Question 17

What metal has to be purified using electrolysis and why?

Answer 17

Copper because it is too impure straight from the furnace and would not conduct electricity which does not make it useful when making electrical wires.

Question 18

Describe how copper is purified using electrolysis.

Answer 18

Electrons are pulled off copper atoms at the anode, causing them to go into the copper sulphate solution as positive copper ions.
Positive copper ions near the cathode (pure copper) gain electrons and turn back into copper atoms. The impurities are dropped at the anode as a sludge, whilst pure copper atoms bond to the cathode.

Question 19

What is a displacement reaction? give an example.

Answer 19

When a more reactive metal is put in a solution contains a less reactive metal. The more reactive metal will kick out the less reactive metal from the solution because it forms stronger bonds with the non-metal part of the solution.
copper sulfate+ iron–> iron sulfate + copper

Question 20

What do we need to do in order to conserve copper-rich ores?

Answer 20

Recycle copper as much as possible, find alternative ways of extracting copper from low- grade ores.

Question 21

Describe what happens in bioleaching?

Answer 21

Bacteria in a copper sulphide solution, gains energy from the bond between copper and sulphate, which separates out the copper from the ore in the process. The bacteria then leaches out a leachate containing copper which can be extracted by filtering.

Question 22

What is phytomining?

Answer 22

Plants are grown in soil containing copper. The plants cannot use or get rid of the copper so it builds up in the leaves. When the plants are harvested and burnt in a furnace the copper can be collected from the ash left in the furnace.

Question 23

What are the problems with bioleaching and phytomining?

Answer 23

They have a smaller impact on the environment but are very slow processes.

Question 24

Why is recycling important?

Answer 24

1/ mining and extracting metals uses a lot of energy which mostly comes from burning fossil fuels.
2/ Fossil fuels are running out so it is important to conserve them, the also contribute to acid rain, global dimming and climate change.
3/ Recycling metals does not need as much energy needed to mine and extract new metal.
4/ Energy is not cheap, saves money.
5/ There is only a finite amount of each metal on earth. We need to conserve these resources as much as possible.
6/ Reduces landfill.

Question 25

Name some properties of metals.

Answer 25

Strong
Can be bent or hammered
Good at conducting heat
Good at conducting electricity

Question 26

Name some metals and what they can be used for

Answer 26

Copper- conducts electricity well, hard, strong, can be bent, doesn’t react with water. Good for electrical wiring.

Aluminium- corrosion resistant, low density, forms hard alloys. Good for making an aeroplane.

Titanium- low density, strong, corrosion resistant. Replacement hips.

Question 27

Why is iron straight from the blast furnace not useful?

Answer 27

It is only 96% iron and is too brittle.

Question 28

Describe the structure of atoms in pure iron.

Answer 28

They are in a regular arrangement and the layers can slide over each other, which makes the iron soft and easily shaped.

Question 29

What is an alloy?

Answer 29

A mixture of metals to make one metal stronger.

Question 30

Name the types of steel and state there properties and uses.

Answer 30

Low-carbon steel easily shaped, car bodies
High- carbon steel hard, flexible, blades and bridges
Stainless steel corrosion resistant, cutlery.