Using Resources Flashcards

Question

What are 3 barrier methods to prevent iron from rusting?

Answer 1

* Painting/coating with plastic - it is ideal for big and small structures and can be decorative * Electroplating - this uses electrolysis to reduce metal ions onto an iron electrode, and can be used to coat the iron with a layer of a different metal that won't be corroded away * Oiling/greasing - this is used for moving parts (e.g. a bicycle chain)

Answer 2

* This involves placing a more reactive metal such as zinc or magnesium with the iron * This means that water and oxygen will react with the sacrificial metal instead of the iron

Answer 3

An object can be galvanised by spraying it with a coating of zinc. The zinc layer is firstly protective but if it's scratched, the zinc around the site of scratch works as a sacrificial metal.

Answer 4

* Without human input * Anything that comes from the earth, sea or air

Answer 5

Some of these natural products can be replaced by a synthetic product or improved upon by man-made processes.

Answer 6

Agriculture provides conditions where natural resources can be enhanced for our needs. For example the development of fertilisers have meant we can produce a high yield of crops.

Answer 7

* Renewable resources reform at a similar rate to (or faster than) we use them - for example, timber is a renewable resource as trees can be planted and only take a few years to grow * Finite resources aren't formed quick enough to be considered replaceable - finite resources include fossil fuels and nuclear fuels

Answer 8

Mining ores is bad for the environment as it uses loads of energy, scars the landscape, produces lots of waste and destroys habitats.

Answer 9

* Many modern materials are made from raw, finite resources * It is a good as it produces useful products * Provides local people with jobs and brings money into the area

Answer 10

Sustainable development is an approach to development that takes account of the needs of present society whilst not damaging the lives of future generations.

Answer 11

One way of reducing the use of finite resources is for people to use less. This not only reduces the use of the resource but also anything needed to produce it.

Answer 12

Chemists can develop and adapt processes that use lower amounts of finite resources and reduce damage to the environment. For example, chemists have developed catalysts that reduce amount of energy required for certain industrial processes.

Answer 13

* A way to improve the sustainability of extracting copper is by extracting it from low-grade ores * Bioleaching * Phytomining * These methods have a much smaller impact however are slow

Answer 14

* Bioleaching is bacteria used to convert copper compounds in the ore into soluble copper compounds, separating out the cooper from the ore in the process * The leachate (the solution produced by the process) contains copper ions, which can be extracted (e.g. by electolysis) or displaced by a more reactive metal (e.g. scrap iron)

Answer 15

* Phytomining involves growing plants in soil that contains copper * Plants can't use or get rid of the copper so it gradually build up in the leaves * The plants then can be harvested, dried and burned in a furnace * The ash contains soluble copper compounds from which copper can be extracted by electrolysis or displaced using scrap iron

Answer 16

* We can conserve the finite amount of each metal by recycling metals * This uses much less energy * This cuts down on the amount of waste getting sent to landfill * This changes the amount of separation required for recyclable metals

Answer 17

Metals are usually recycled by melting them and casting them into the shape of the new product.

Answer 18

*Glass recycling can help sustainability by reducing the amount of energy needed to make new glass products and also the amount of waste created when glass is thrown away * Glass bottles can be reused without reshaping * Other forms of glass can't be reused so they are recycled instead (usually the glass is separated by colour and chemical composition before being recycled) * The glass is crushed and then melted to be reshaped for use in glass products (e.g. bottles, jars, insulating glass wool)

Answer 19

A life cycle assessment looks at every stage of a product's life to assess the impact it would have on the environment.

Answer 20

1. Getting the raw materials * extracting raw materials needed for a product can damage the local environment * extraction can also result in pollution due to the amount of energy needed * raw materials often need to be processed to extract the desired materials and this often needs large amounts of energy 2. Manufacture and Packaging * manufacturing products and their packaging can use a lot of energy resources and can also cause a lot of pollution * you also need to think about waste products and how to dispose them * the chemical reactions used to make compounds from their raw materials can produce waste products * some waste can be turned into other useful chemicals , reducing the amount that ends up polluting the environment 3. Using the product * the use of a product can damage the environment (e.g. fertilisers can leach into streams and rivers causing damage to ecosystems) * how long a product is used for or how many uses it gets * products that require lots of energy to produce but are used for ages means less waste in the long run 4. Product disposal * products often disposed in landfill sites this takes up space and pollutes land and water * energy is used to transport waste to landfill which causes pollutants to be released into atmosphere * products might be incinerated (burnt) which causes air pollution

Answer 21

* The use of energy, some natural resources and the amount of certain types of waste produced by a product over it's lifetime can be easily quantified but the effect of some pollutants is harder to give numerical values * A life cycle assessment is not an objective method as it takes into account the values of the person carrying out the assessment meaning the life cycle assessments can be biased * Selective life cycle assessments only show some of the impacts of a product on the environment can also be biased as they can be written to deliberately support the claims of a company in order to give them positive advertising

Answer 22

Potable water is water that's been treated or is naturally safe for human's to drink. It's essential for life.

Answer 23

Potable water is not pure as it contains lots of dissolved substances other than H2O molecules.

Answer 24

* The pH is between 6.5 and 8.5 * There isn't any other microbes swimming in it

Answer 25

Rainwater is a type of fresh water.

Answer 26

Fresh water is water that doesn't have much dissolved in it.

Answer 27

When it rains, water can either collect as surface water or as groundwater.

Answer 28

* Lakes * Rivers * Reservoirs

Answer 29

Rocks called aquifers that trap water underground.

Answer 30

The source of freshwater depends on the location.

Answer 31

* Filtration - a wire mesh screens out large twigs etc, and then gravel and sand beds filter out any other (smaller) solid bits * Sterilisation - the water is sterilised to kill any harmful bacteria or microbes and can be done by bubbling chlorine gas through it or using ozone or ultraviolet light

Answer 32

In dry countries (e.g. Kuwait), they use sea water.

Answer 33

Desalination is the name of the process to treat sea water.

Answer 34

* First, test the pH of the water using a pH meter and neutralise it to required pH - you can neutralise it with a titration * Second, test the water for the presence of sodium chloride (main salt in seawater) * To test for sodium ions by doing a flame test on a small sample and if sodium ions are present the flame turns yellow * To test for chloride ions you take another sample and add a few drops of dilute nitric acid followed by a few drops of silver nitrate solution and if chloride ions are present a white precipitate will form * Third, to distil water, pour salty solution into a distillation apparatus and heat flask from below, the water will boil forming steam leaving any dissolved salts in the flask as the steam condenses back to liquid water in the condenser and can be collected * Forth, retest the distilled water for sodium chloride to check it has been removed and also retest the pH to check it's neutral (pH of 7)

Answer 35

We use meters rather than indicators as this won't contaminate the water.

Answer 36

The sea water is passed through membrane that only allows water molecules to pass through. Ions and larger molecules are trapped by the membrane and are separated from the water.

Answer 37

Desalinating water requires loads of energy. This means that it is really expensive and not practical for producing large quantities of fresh water.

Answer 38

When water is flushed down a drain, it goes into the sewers and towards the sewage treatment plants.

Answer 39

Agricultural systems produce a lot of waste water including nutrient run-off from fields and slurry from animal farms.

Answer 40

Sewage from domestic or agricultural sources have to be treated to remove any organic matter and harmful microbes before it can be put back into freshwater sources.

Answer 41

It would make freshwater sources very polluted and would pose health risks.

Answer 42

An example of an industrial process that produces a lot of waste water that needs to be collected and treated is the Haber Process.

Answer 43

Industrial waste water need to undergo additional stages of treatment because it contains harmful chemicals.

Answer 44

* First, the sewage is screened to remove any large bits of material like twigs, plastic bags and grit * Second, it's then allowed to stand in a settlement tank and undergoes sedimentation - the heavier suspended solids sink to the bottom to produce sludge while the lighter effluent floats on top * The effluent in the settlement tank is removed and treated by biological aerobic digestion - this is when air is pumped through the water to encourage aerobic bacteria to break down any organic matter including other microbes in the water * The sludge from the bottom of the settlement tank is also removed and transferred into large tanks - here it gets broken down by bacteria in the process anaerobic digestion * Anaerobic digestion breaks down the organic matter in the sludge, releasing methane gas in the process - the methane gas can be used as an energy source and the remaining digested waste can be used as a fertiliser * For waste water containing toxic substances, additional stages of treatment may involve adding chemicals, UV radiation or using membranes

Answer 45

* The Haber process is used to make ammonia from hydrogen and nitrogen * N2(g) + 3H2(g) ⇌ 2NH3(g) (+ heat)

Answer 46

The Haber process is well suited for an industrial scale as the reactants aren't too difficult or expensive to obtain.

Answer 47

* The nitrogen is obtained easily from the air, which is 78% nitrogen * The hydrogen mainly comes from reacting methane with steam to form hydrogen and carbon dioxide * The reactant gases are passed over an iron catalyst - a high temperature of 450°C and a high pressure of 200 atmospheres are used * Because the reaction is reversible, some of the ammonia produced converts back into hydrogen and nitrogen again and it eventually reaches a dynamic equilibrium * Ammonia is formed as a gas, but as it cools in the condenser it liquefies and is removed - the unused hydrogen and nitrogen are recycled so nothing is wasted * The ammonia produced can be used to make ammonium nitrate which is a very nitrogen-rich fertiliser

Answer 48

1) Temperature 2) The concentration of a solution or the pressure of a gas 3) Surface area - this changes depending on the size of the lumps of solid 4) The presence of a catalyst

Answer 49

A trade-off between increasing the rate and maximising the yield of a reaction.

Answer 50

Exothermic.

Answer 51

* This means increasing temperatures will move the equilibrium the wrong way (away from ammonia and towards nitrogen and hydrogen) - so the yield of ammonia would be greater at lower temperatures. * However, lower temperatures means a slower rate of reaction (this means equilibrium is reached more slowly)

Answer 52

It is a compromise between maximum yield and speed of reaction.

Answer 53

This would move the position of equilibrium towards the products since there are 4 molecules of gas on the left-hand side for every 2 on the right - so increasing pressure maximises the percentage yield and also increases the rate of reaction

Answer 54

To make pressure as high as possible without making the process too expensive or too dangerous to build and maintain.

Answer 55

With manure.

Answer 56

* They are more widely available * Easier to use * They don't smell * They have just enough of each nutrient so more crops can be grown

Answer 57

1) Nitrogen 2) Phosphorus 3) Potassium If plants don't get enough of these elements, their growth and life processes will be affected.

Answer 58

Replace missing elements in the soil or provide more of them. This helps to increase crop yield as the crops can grow faster and bigger.

Answer 59

They are formulations containing salts of nitrogen, phosphorus and potassium in the right percentages of the elements.

Answer 60

When ammonia is reacted with oxygen and water in a series of reactions.

Answer 61

When ammonia is reacted with acids (including nitric acid)

Answer 62

Ammonia and nitric acid reacted together. This is an especially good compound to use in a fertiliser because it has nitrogen from 2 sources.

Answer 63

NH3 + HNO3 ---> NH4NO3

Answer 64

There are 2 ways: 1) In Industry - the reaction is carried out in giant vats at high concentrations resulting in a very exothermic reaction ; the heat released is used to evaporate water from the mixture to make a very concentrated ammonium nitrate product 2) In the Lab - the reaction is carried out on a much smaller scale by titration and crystallisation ; the reactants are at a much lower concentration than in industry so that less heat is produced by the reaction and it's safer for a person to carry it out ; after the titration, the mixture then needs to be crystallised to give pure ammonium nitrate crystals

Answer 65

Crystallisation isn't used in industry because it is very slow.

Answer 66

Extracted by mining and are used as a source of potassium.

Answer 67

By mining however plants can't use them as nutrients because the phosphate rocks in them are insoluble.

Answer 68

1) A reaction with nitric acid produces phosphoric acid and calcium nitrate 2) A reaction with sulphuric acid produces calcium sulphate and calcium phosphate (this mixture is known as single superphosphate) 3) A reaction with phosphoric acid only produces calcium phosphate (the product of this reaction can be called triple superphosphate)