Using resources

Question 1

What is potable water?

Answer 1

Potable water is water that is drinkable by humans

Question 2

Is potable water pure?

Answer 2

No, there is not just H20 in there. There are also dissolved substances - just low levels of them.

Question 3

What is freshwater?

Answer 3

Freshwater does not have as many substances in it and can be collected easily.

Question 4

What are sources of freshwater?

Answer 4

Rivers, reservoirs, lakes, rainfall.

Question 5

How do you treat freshwater?

Answer 5

First, you filter the water to remove unwanted materials. Next, you bubble chlorine through it to sterilize it from microbes.

Question 6

Why might you need to desalinate seawater?

Answer 6

It contains high levels of salt and there might not be freshwater near you.

Question 7

What are some drawbacks of desalination?

Answer 7

It is very expensive.

Question 8

What can be used to desalinate seawater?

Answer 8

Distillation.

Question 9

How does one distil seawater in a lab?

Answer 9

First, find the pH of the water and if it is too high or too low - use titration. Then, test the water for sodium chloride using the test for sodium ions and the test for chloride ions. Then you can distil it again but after this, you should retest it for pH and sodium chloride.

Question 10

What is reverse osmosis?

Answer 10

When seawater is passed through a membrane that only allows water molecules to pass through. Ions and larger molecules are trapped by the membrane.

Question 11

Why might we need to treat wastewater?

Answer 11

So that it does not pollute the environment and so we can have access to clean water.

Question 12

Where can wastewater come from?

Answer 12

Houses, Haber process, Sewage, Industrial wastewater with harmful chemicals

Question 13

What is the first step in wastewater treatment?

Answer 13

Screening. It involves removing large bits of material like twigs or grit.

Question 14

What is the second step in wastewater treatment?

Answer 14

Sedimentation. The water will go into a settlement tank where the heavier solids sink to the bottom to produce sludge. The lighter effluent stays at the top.

Question 15

What happens to the effluent?

Answer 15

It is treated by biological aerobic digestion where aerobic bacteria are encouraged to break down organic matter and other microbes.

Question 16

What happens to the sludge?

Answer 16

Transferred to large tanks and is broken down by anaerobic digestion. It releases methane gas and it turns into fertilizer.

Question 17

What is the Haber process?

Answer 17

It is used to make ammonia from hydrogen and nitrogen for fertilizer.

Question 18

What is the equation for the Haber process?

Answer 18

N2 +3H2 2NH3 + (heat)

Question 19

What are the conditions for the Haber process?

Answer 19

200 atm and 450 degrees celsius.

Question 20

What is it passed over?

Answer 20

An iron catalyst.

Question 21

What kind of reaction is it and why is this important?

Answer 21

Reversible, so some of the ammonia is converted back to hydrogen and nitrogen so they are recycled.

Question 22

What is the compromise of heat in the Haber Process?

Answer 22

As the forward reaction in the Haber process is exothermic the more heat there is the equilibrium will move away from Ammonia. But the lower the temperature the slower the rate of reaction. The compromise is between speed and maximum yield.

Question 23

What is the compromise of pressure in the Haber process?

Answer 23

As increasing pressure shifts the equilibrium to the products it is good for a higher pressure but this costs more so there must be a balance between yield and cost of production.

Question 24

What are NPK fertilizers?

Answer 24

Formulated fertilizers provide plants with the essential elements for plant growth.

Question 25

What does NPK stand for?

Answer 25

Nitrogen (N) Phosphate (P) Potassium(K)

Question 26

How do you make the nitrogen compounds?

Answer 26

React ammonia with oxygen and water to make nitric acid and then react that with ammonia again to get ammonium nitrate?

Question 27

What is the equation for ammonia + nitric acid

Answer 27

NH3 (aq) + HNO3 (aq) -> NH4N03 (aq)

Question 28

What can be mined as a source of potassium?

Answer 28

Potassium sulfate and Potassium Chloride.

Question 29

Phosphate rock is also mined but is insoluble. What does it react with to produce soluble sulfates.?

Answer 29

Nitric acid -> phosphoric acid + calcium nitrate
Sulfuric acid -> calcium sulfate and calcium phosphate (single superphosphate)
Phosphoric acid-> Calcium phosphate (triple superphosphate)

Question 30

What are ceramics?

Answer 30

Ceramics are non-metal solids with high melting points that are not made from carbon-based compounds.

Question 31

What are some examples of ceramics?

Answer 31

Clay and glass.

Question 32

What are composites?

Answer 32

Composites are one material embedded in another. Fibres or fragments are surrounded by a matrix acting as a binder.

Question 33

What are some examples of composites and what are their uses?

Answer 33

Fibreglass is low density like plastic but strong like glass and is used for skis and boats.
Concrete is made from a mixture of sand and gravel embedded in cement. It is good for building material.

Question 34

What influences the properties of a polymer?

Answer 34

How it is made and what it is made from.

Question 35

What are thermosetting polymers?

Answer 35

They contain monomers that form cross-links with polymer chains. They are strong, hard, and rigid.

Question 36

What are thermosoftening polymers?

Answer 36

These contain individual polymer chains entwined with weak forces. These can be melted and remolded.

Question 37

What is the difference between low and high-density polyethene?

Answer 37

The low density is made from ethene at a moderate temperature with high pressure. High-density ethene is formed at a lower temperature with a catalyst/

Question 38

What are ceramics good for?

Answer 38

They are insulators, brittle and stiff.

Question 39

What are composites good for?

Answer 39

Due to their nature, they can be good for many things.

Question 40

What are metals good for?

Answer 40

They are malleable, conductors, ductile (good for wires) and shiny so are good for cars, cutlery and wires etc.

Question 41

What are polymers good for?

Answer 41

They are insulators and can be easily molded as they are flexible so are food for clothing and electrical items.

Question 42

What are alloys?

Answer 42

Alloys are when metal meets another metal and the structure changes to harden. They can be more useful in everyday life as they can be stronger and of lower density.

Question 43

What is corrosion?

Answer 43

It is where metals react to substances in their surroundings and are gradually destroyed.

Question 44

What is it called when iron corrodes?

Answer 44

Rusting.

Question 45

What is the formula for rust?

Answer 45

iron + oxygen = water -> hydrated iron oxide

Question 46

How do you prevent rust?

Answer 46

Sacrificial metals such as zinc react with the oxygen meaning iron does not
Coating it with plastic. oiling and greasing.

Question 47

What are life cycle assessments?

Answer 47

They show total environmental costs during a product’s entire life.

Question 48

What are the stages of an LCA?

Answer 48

Getting the raw maeterails, manufacturing and packaging, using the product and product disposal.

Question 49

What are some problems with life cycle assessments?

Answer 49

It can show the bias of the person carrying out the assessment. It can be hard to show the numerical value of damage done by pollutants. Selective LCAs carried out by companies can deliberately support themselves.