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New(9-1) AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers

This page contains the AQA GCSE Chemistry The Earth’s Resources Questions and kerboodle answers for revision and understanding The Earth’s Resources .This page also contains the link to the notes and video for the revision of this topic. 



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C
14.1 Finite and renewable resources AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers Page No. 207

  1. Answer.

Renewable energy sources are one which don’t run out- which can be renewed. We can keep using them and using them, and we will never run out. Example of renewable sources include wind, water power and solar power.

Finite energy sources are one which do run out. As we use them to generate energy, they get used up, and can’t be used a second time. There are three main non renewable energy sources which are fast running out: coal, oil and natural gas.

  1. a. Answer.

Fossil fuels and metal ores are examples of non-renewable resources.

  1. Answer.

Example of renewable sources includes wind, water power.

  1. a. Answer.

Polythene is non renewable because it cannot be recycled again. Plastic is a strange one in the area of renewability. In most cases it is made from oil and natural gas, which are nonrenewable (do not naturally regenerate their supply) however alternate plastics can be made from starches or cellulose which is a renewable source of raw materials as they are derived from plants.

  1. a. Answer

If the rate of use is of the order 2013 then the fossil carbon will last

=(1.5 X 1016)/(9.2 X 1019)

=1.6 X 106 years

  1. Answer

The order of magnitude of the time left before the fossil reserves run out :

=(5.5 X 1012)/(1X 1010)

= 550 years

  1. Answer

The two reasons why the estimations can be expressed as order of magnitudes are:-

  1. There are uncertainties involved in the calculations
  2. The predictions do not take into account the recycling of resources which will be significant in the future.



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 C 14.2 Water safe to drink AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers Page No. 209

    

  1. Answer.

Water could be made portable by three ways are as follows:

  1. Passing the untreated water through filter beds made of sand and gravel to remove solids particles.
  2. The addition of chlorine or ozone to sterilize the water by killing microorganisms Without adding chemical sterilizing agents.
  3. By passing ultraviolet light through the water.
  4. a. Answer.

Water can be converted from natural source into pure water by distillation or reverse osmosis.

  1. Answer.

Remove a small amount of the water you wish to sample from its source. The less water there is to test, the more accurate the reading will be. Dip the pH strip into the isolated water sample you wish to test for. After a moment, the strip should change color.

Remove the strip from the sample and observe the color on the end of the strip. Refer to the color chart that came with your pH testing kit. Pure water has a pH level of 7. If the color on your test strip doesn’t match the color for a neutral pH level of 7, your water sample isn’t pure and contains foreign materials.

 1.Answer

Anhydrous copper sulphate or blue cobalt chloride are not used as the test for the purity of water as they only detect the presence of water and not the purity of water.

 

  1. Answer

The bottled water sold in the supermarket is not described as pure water as it has dissolved minerals added to it and it is not 100% pure.

 

  1. A. Answers

There is a shortage of water even in the areas of large coastlines as the water present is salty rather than fresh water and large amount of resources are required to desalinate the water.

  1. Answers

Desalination is the processes that remove the excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption or irrigation

  1. i. Answer-The main disadvantage of desalination using distillation-The cost is high- meaning that it costs hundreds and thousands of dollars just to clean a small amount of water. It also costs a lot to create the plants.
  2. Answer.

The other process instead of distillation that can be used to purify water is Reverse osmosis.


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C 14.3 Treating wastewater AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers  Page No. 211

 1.a. Flowchart of Sewage Treatment

2.a. Answer.

In the primary treatment there is a circular tank in which the solid sediments are allowed to settle out from the mixture. Large paddle rotates and push the solids toward the center of the tank. Then the sludge is piped to a storage tank for further treatment.

  1. Answer

Sewage sludge can be dried and used as a fertilizer on farmland to improve the soil. The sludge can be dried and burnt into a crusty solid cake that can be burnt to generate electricity.

 3.Answer.

In secondary tank the useful bacteria feed on any remaining organic matter and harmful microorganisms still present breaking them down aerobically. The sewage sludge is separated broken down by anaerobic digestion and dried. It can provide us with fertilizer and a source of renewable energy.

  1. Answer

For humans, drinking water should have

sufficiently low levels of dissolved salts and

microbes. Water that is safe to drink is called

potable water.

Potable water is not pure water in the chemical

sense because it contains dissolved

Substances.

Use of salt water from an aquifier as source of

potable water

Potable water can be made from sea water,

through a process known as

desalination.

It is preferable to make potable water from

fresh water reserves rather than

from sea water. This is because removing the

large amount of sodium

chloride requires a lot of energy.

Desalination can be done by distillation and by

reserve osmosis.

Use of waste water from an aquifier as source of

potable water

Waste water or recycled water for reuse

applications instead of using

freshwater supplies can be a water-saving

measure.

When used water is eventually discharged back

into natural water sources, it

can still have benefits to ecosystems, improving

streamflow, nourishing plant

life and recharging aquifers, as part of the

natural water cycle.

Wastewater reuse is a long-established practice

used for irrigation, especially

in arid countries.

Reusing wastewater as part of sustainable water

management allows water to

remain as an alternative water source for human

activities. This can reduce

scarcity and alleviate pressures on groundwater

and other natural water

bodies.


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C 14.4 Extracting metals from ores AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers: Page No. 213

 1.Answer.

Copper is important because it plays a role in  technology and the economy. Copper is used to help create hybrid vehicles, mobile phones and tablet computers.

  1. Answer.

Two traditional ways of extracting copper metal are:

By electrolysis

By smelting

  1. Answer. It is beneficial to extract copper using bacteria over traditional methods. Bioleaching is in general simpler and, therefore, cheaper to operate and maintain than traditional processes, since fewer specialists are needed to operate complex chemical plants.

The process is more environmentally friendly than traditional extraction methods. For the company this can translate into profit, since the necessary limiting of sulfur dioxide emissions during smelting is expensive.

1.Answer.

Copper is an unreactive metal – it reacts only slowly with the atmosphere. This means that huge lumps of copper metal are found buried in the ground as nuggets. This is called native copper. Native copper isn’t mined because there is so little of it. Therefore it is of little commercial importance.

  1.  
  2. Answer.

Copper is purified by electrolysis and during electrolysis pure copper is deposited at cathode i.e negative electrode from where the pure copper can be collected.

3.Answer. Balanced chemical equation and ionic equation of extraction of copper using iron sulphate

Fe(s) + CuSO4 (aq) ® FeSO4 (aq) + Cu(s)

Fe(s) + Cu+2(aq) ® Fe+2(aq) + Cu(s)

  1. a. Answer. A reductionelectrode reaction at the negative cathode

(–) Cu2+(aq) + 2e– ==> Cu(s) (copper deposit, reduction – 2 electrons gained)positive ion reduction by electron gain

An oxidation electrode reaction at the positive anode

(+) Cu(s) – 2e– ==> Cu2+(aq) (copper dissolves, oxidation – 2 electrons lost)or  Cu(s) ==> Cu(s) + 2e–  Atom oxidation by electron loss

  1. b. Answer.

At negative cathode reduction occur and at positive electrode oxidation occur.

Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.

Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.

 

  1. Answer.
  • Some plants absorb copper compounds through their roots. They concentrate these compounds as a result of this. The plants can be burned to produce an ash that contains the copper compounds. This method of extraction is called phytomining. The copper ions can be leached  from the ash by adding sulfuric  acid.This make a solution (leachate) of copper sulfate. Displacement by scrap iron and then electrolysis make pure copper metal.
  • This method will become increasingly important because:
  • The possibility of the recovery and re-use of valuable metals (by companies specializing in “phytomining”)
  • It is potentially the least harmful method because it uses naturally occurring organisms and preserves the environment in a more natural state.


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C 14.5 Life cycle assessment AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers: Page No. 215

1.Answer.

The stages of life cycle assessment include :-

  1. a) Raw Materials Extraction
  1. b) Manufacture
  1. c) Use/ Reuse/ Maintenance
  1. d) Recycle//Waste Management
  2. Answer.

LCA is carried out on new products to assess the environmental impact of the products, process or services.

  1. A Answer

The bauxite ore will be the raw material to

produce aluminium.

b(i) Carbon dioxide

(ii) Sulphur Dioxide

  1. Answers

LCA may not be totally objective as assigning the numerical values of different environmental aspects is subjective.


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C 14.6 Reduce, reuse and recycle AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers: Page No. 217

 1.Answer.Rehabilitation is a legal requirement for mining companies in order to sustain the environment. Rehabilitation procedures include:
– drill holes are capped to stop local fauna falling down the holes.
– back filling trenches to support rehabilitation.
– lining tailing ponds with earth to soak up spillage or lining it to prevent seepage.

  1. Answer.

We could run an electric fire  for 56 hours on the energy you have saved.

  1. Answer.

Recycling undeniably provides benefits to the environment in terms of the sustainability of resources and also the reduction of landfill and waste disposal activities. It is, therefore, important to analyse its worth in terms of economic benefits and energy benefits and whether recycling metals is more economic or energy-efficient than producing aluminium from its ore. What makes aluminium one of the easiest and most appropriate material to recycle is that it can be recycled an infinite number of times without compromising the quality of the material. This is different to materials, such as paper, which can only be recycled a certain number of times before it becomes futile. To produce one tonne of aluminium, four tonnes of bauxite, the ore from which aluminium is extracted, is needed. By implementing aluminium recycling, there are significant decreases in the need for placing valuable resources into landfill, never to be used again. This reduces landfill costs and also takes some stress off the environment.

  1. Answer.

The process of copper recycling is more difficult as copper is often alloyed with other metals for example in brass the copper is mixed with zinc. to date only about 12% of known copper resources have been mined. However copper ore is a finite resource and it makes sense to conserve ore by recycling. It is cheaper to recycle old copper than to mine and extract new copper.

  1. Answer.
  • Due to recycling less Greenhouse gasses such as Carbon Dioxide, Carbon Monoxide, Nitrous Oxide and Water Vapour are being produced each year. Although global warming has not been halted, the extent of its effects are being lessened through recycling and so we are preserving the Earth for our children and our children’s children
  • Recycling metal can aid in the prevention of visual pollution. Metal is acquired through the mining of metal ores and most metal ores are found in untouched, desolate landscapes
  • Chemical pollution is also reduced by recycling metals as it cuts down on the amount of transport that is used.

 



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Summary Questions AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers: Page No. 218

  1. a. Answer.

The boiling point reduces by reducing the pressure. So to reduce the boiling point, the pressure is reduced so that less energy is required in boiling.

1.Answer.

In the desalination process, high temperatures and salt solutions are used which increases the rusting process.

2.Answer.

Flash distillation involves boiling which is dependent on fossil fuels to produce high temperature. Reverse osmosis saves money by decreasing the dependency on fossil fuels for energy.

 

3.a. What name is given to the method of extracting copper from an ore:

  1.  
  2. Answer.

Bioleaching is the process of extracting copper from bacteria.


  1. Answer.     Phytomining is the process of extracting copper from plants.
    iii. Answer-    Smelting is the process of extracting copper by roasting.
  2. Answer- Electrolysis is the process of extracting copper by electricity.
  1. Answer.

Bioleaching and phytomining are the process to extract copper from low-grade copper ores.

  1. Using the methods named in both part a ii and part a iv above, explain in detail whether copper in the ore is reduced or oxidised. Include half equations in your answer to both methods, assuming the method in part a ii is carried out on copper() sulfide. [6 marks]
  2. Answer

In roasting Copper sulphide is roasted to give copper and sulphur dioxide.

Cu2S(s) + O2(g) → 2Cu(s) + SO2(g)

In the equation above, copper ions gain an electron and reduced to copper atom

The half equation for the above process is

Cu+(s) + e =  Cu(s)

In the electrolysis process, copper 2+ ions are formed which also get reduced by gaining two electrons

Cu2+(s) + 2e =  Cu(s)

 

  1. Describe the advantages and disadvantages of using bioleaching to extract copper metal. [6 marks]
    Bioleaching is the process of extracting copper from bacteria. It has both advantages and disadvantages.


ADVANTAGES 

  1. It requires less energy than other methods like roasting or electrolysis for extracting copper
  2. It can extract copper from low grade ores
  3. It can extract copper from trash
  4. It saves energy cost, land resource.


DISADVANTAGES

  1. It is a longer process and takes more time in extraction
  2. It is not technologically advanced.

4 a. Answer.

Average mass of metal in a car = 869 kg

  1. Percentage of metallic materials = 68.3 + 6.3 + 1.5

=76.1

Percentage of non-metallic materials = 100-76.1

Answer-23.9%

C i. Answer-Steel or iron are the main metals found in cars.

Ii. Answer. Metals are magnetic so this property can help the metals to be separated from the non metals.

5 a. i. Answer.

Gold alloy (in carat) is the independent variable.

  1. Answer.

Maximum hardness of the alloy is Continuous variable

  1. Answer.

As the proportion of gold in the alloy increases, hardness increases up to about 18 carat, then decreases.

  1. i. Answer.

Copper sulphide when roasted produces Sulfur dioxide which can cause acid rain.

  1. Answer.

Gold ore or the use of  fossil fuels in the process can cause depletion of natural resources.



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Practice Questions AQA GCSE Chemistry C14 The Earth’s Resources Kerboodle Answers: : Page No. 219

 01.1 Answer.

During stage 1 of the sewage treatment Solids are removed.

01.2. Answer.

Chlorine can be added to sterilize water in stage 2.

01.3. Answer.

The water is not pure as it Contains dissolved solids, chemicals, minerals and gases like oxygen.

 

01.4 Distillation is the technique to obtain pure water from salty water.

01.5. Evaporation occurs at A.
01.6. Condensation occurs at B.

01.7. Distillation is not always used to purify water from sea water as distillation requires a lot of energy and so has a dependency on fossil fuels and is considered expensive.

 01.8 Answer. We can test the purity of drinking water by making it evaporate in  a dish and monitoring it for a few days. If all the water evaporates then it is considered to be pure water.

Answer 2 .

Advantages of bags made from corn starch

Corn starch is made from plants which can be regrown or replanted therefore are renewable. The energy requirement for making bags from corn starch is lower. The carbon footprint for bags from corn starch is lower or making bags from cornstarch releases less CO2 into the atmosphere. Plants will take CO2 out of the atmosphere as they photosynthesise or grow. Bags made from corn starch are biodegradable so will decompose in landfill sites so there is less of a problem with landfill sites filling up.

Bags made from corn starch are compostable so don’t have to be put in landfill sites. Bags made from corn starch cause less of a problem with litter.

Disadvantages of bags made from corn starch

The manufacturing process takes longer. The bags may degrade too quickly or can be used fewer times before they degrade.

Advantages of bags made from poly(ethene)

The bags can be manufactured more quickly. The bags can be used more times before they degrade. The bags can be disposed of by burning which produces energy.
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References:

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