Chemistry 1A - Products From Rocks

Question 0

What are the vertical columns called on the periodic table?

Answer 0

Groups

Question 1

Name and describe all the parts of an atom.

Answer 1

Nucleus - in the centre of the atom

Protons - positively charged, found in the nucleus

Neutrons - no charge, found in the nucleus

Electrons - move around the nucleus and are negatively charged. They occupy shells around the nucleus.

Question 2

What is made when atoms are chemically joined together?

Answer 2

A compound.

Question 3

What is limestone mainly made of?

Answer 3

Calcium carbonate

Question 4

What happens when limestone is heated? And whats the equation?

Answer 4

It thermally decomposes.

Calcium carbonate –> calcium oxide + carbon dioxide

CaCo3(s) –> CaO(s) + CO2(g)

Question 5

What elements decompose in the same way as limestone?

Answer 5

Magnesium, copper, zinc, sodium carbonates.

Question 6

What is the equation for when calcium carbonate reacts with sulfuric acid?

Answer 6

Calcium carbonate + sulfuric acid –> calcium sulfate + carbon dioxie + water

CaCO3 + H2SO4 –> CaSO4 + CO2 + H2O

Question 7

What is produced when calcium oxide reacts with water? And how can it be used?

Answer 7

Calcium hydroxide. It is an alkali which can be used to neutralise acidic soil in fields and can also be used to test for CO2. If you make a solution of calcium hydroxide and water (limewater) and bubble it through a solution, the solutions will go cloudy if CO2 is present. The cloudiness is due to the formation of calcium carbonate.

Question 8

Name 5 problems quarrying limestone causes.

Answer 8

1) ugly holes in the landscape
2) quarrying explosions produce lots of noise and dust
3) destroys lots of animal habitats
4) transport of limestone using big lorries produces lots of noise and pollution
5) waste materials produce unsightly tips

Question 9

Name 5 benefits of limestone.

Answer 9

1) produces things people want - houses, roads, dyes, paints and medicines
2) acidity in lakes, rivers and soil can be neutralised by limestone products
3) it is used in power station chimneys to neutralise sulfur dioxide
4) quarrying provides jobs
5) once quarrying is complete, landscaping and restoration is usually required

Question 10

What is a metal ore?

Answer 10

A rock which contains enough metal to make extraction worthwhile.

Question 11

How can a metal be extracted from an ore?

Answer 11

By reduction or electrolysis.

Question 12

What happens when an ore is reduced?

Answer 12

Oxygen is removed

Question 13

What metals can be extracted from ores using electrolysis and what metals can be extracted from ores using reduction?

Answer 13

Metals higher than carbon in the reactivity series have to be extracted using electrolysis and metals below carbon in the reactivity series can be extracted by reduction using carbon.

This is because carbon can only take oxygen away from metals which are less reactive than carbon itself.

Question 14

What is the definition of electrolysis?

Answer 14

Splitting up with electricity

Question 15

Name the 2 new methods of extracting copper.

Answer 15

Bioleaching - it uses bacteria to extract copper from copper sulfide. The bacteria get energy from the bond between copper and sulfur, separating out the copper from the ore in the process. The leachate (the solution produced by the process) contains copper, which are extracted by filtering.

Phytomining - growing plants in soil that contains copper. The plants cant use or get rid of the copper, so it just builds up in the leaves. The plants are harvested, dried and burned in a furnace, copper is collected from the ash.

Question 16

Name 6 reasons why recycling metal is important:

Answer 16

1) mining metals takes a lot of energy
2) fossil fuels are running out, so its important to conserve them
3) recycling metals use a lot less energy than extracting metals
4) saves money
5) there’s a finite amount of metal on Earth, so recycling them conserves resources
6) reduces landfill

Question 17

Name the basic properties of metals

Answer 17

Strong, malluable, conduct heat, conduct electricity

Question 18

Name the properties of copper

Answer 18

• good conductor of electricity (good for wires)
• hard, strong
• can also be bent
• doesn’t react with water

Question 19

Name the properties of aluminium:

Answer 19

• corrosion resistant
• low density
• not strong, but forms strong alloys

Question 20

Name the properties of titanium:

Answer 20

• light weight
• low density
• very strong
• corrosion resistant

Question 21

What metal is used for hip replacements, and why?

Answer 21

Titanium because its light weight and doesn’t corrode

Question 22

What is an alloy?

Answer 22

A mixture of different metals which are more suited to particular uses

Question 23

Name 3 types of steels and their proterties/uses:

Answer 23

Low carbon steel: easily shaped, car bodies

High carbon steel: very hard and inflexible, blades and bridges

Stainless steel: corrosion-resistant, cutlery and containers of corrosive substances

Question 24

Why are alloys harder than pure metals?

Answer 24

Because different elements have different sized atoms, so when an element such as carbon is added to pure iron, the smaller carbon atom will upset the layers of pure iron atoms, making it more difficult for them to slide over each other, so alloys are harder.

Question 25

What is crude oil a mixture of?

Answer 25

Hydrocarbons

Question 26

What size molecules condense at the top of the fractioning column?

Answer 26

Shorter molecules condense nearer the top of the fractioning column, longer ones at the bottom

Question 27

Crude oil is mostly ………..

Answer 27

Alkanes

Question 28

Name the first 4 alkanes

Answer 28

Methane, ethane, propane, beutane

Question 29

What are the basic trends of alkanes?

Answer 29

1) the shorter the molecules, the less viscous it is
2) the shorter the molecules, the more volatile (they turn into a gas at a lower temperature)
3) the shorter the molecules, the more flammable

Question 30

What is the general alkane formula?

Answer 30

CnH2n+2

Question 31

Name the 3 alternative fuels to using crude oils and list pros and cons:

Answer 31

1) ETHANOL - produced from plant material.
Pros: carbon neutral Cons: engines need to be converted for it to work and it isnt widely available

2) BIODIESEL - produced from vegetable oils
Pros: carbon neutral, engines don’t need to be converted Cons: expensive

3) HYDROGEN GAS - get hydrogen from the electrolysis of water
Pros: very clean, just water Cons: special, expensive engine is needed