CIO Using Resources

What do humans rely on Earth's resources for? [4]

- Warmth - Shelter - Food - Transport

What do all our resources come from?

Earth's crust, oceans and atmosphere

What is a finite resource?

Non-renewable

What is an example of a finite resource?

Metal ores

What are renewable resources?

Resources that can be replenished

What is an example of renewable resources?

Timber

Why should care be taken with non-renewable resources?

To ensure they do not pollut the planet.

What was the abundancy of natural resources like in the past?

Natural resources were sufficient to provide the human population with food, timber, clothing and fuels

What has happened as the population of humans have increased?

Humans have come to rely more on agriculture to supplement or even replace resources

How does Chemistry play an important role in improving agricultural and industrial processes? [2]

- Allows new products to be developed - Contributes to sustainable development

What is sustainable development?

Development that meets the needs of the current generation without comprimising the ability of future generations to meet their own needs

Is water of the correct quality essential for life?

Yes

What does water naturally contain?

Microorganisms and dissolved salts

Why does there need to be low levels of microorganisms and dissolved salts in water?

So its safe for humans to drink

What does fresh water contain?

Low levels of dissolved salts

What does the term potable mean?

Water that is good quality and safe to drink

In the UK, how is potable water produced? [4]

- Fresh water from a suitable source (lake or river) is collected - Passed through a filter bed to remove solid particles - Chlorine gas is added to kill any harmful microorganisms - Fluoride is added to drinking water to reduce tooth decay

Why is too much fluoride bad?

Can cause discolouration of teeth

What does ozone and ultraviolet do to water?

Sterlises water

How do you improve the taste and quality of tap water?

By removing more dissolved substances by passing the water through a filter containing carbon, silver and iron exchange resins

What would happen if fresh water supplies are limited? [2]

- Seawater can be desalinated to produce pure water. - This can be done by distillation or reverse osmosis

What is the con of reverse osmosis and desalination when attempting to produce pure water?

Both of these processes require lots of energy, thus making them very expensive

What happens during distillation? [2]

- Water is boiled to produce steam - Steam is condensed to produce pure liquid water

What does pure water contain?

No dissolved substances

What are large amounts of waste water produced by? [3]

- Homes - Agricultural processes - Industrial processes

What must happen to waste water before it can be released back into the enviroment?

Must be treated

What does sewage treatment include? [4]

- Screening and grit removal - Sedimentation to produce sewage sludge and effluent - Anaerobic digestion of sewage sludge - Aerobic biological treatment of effluent

Why is copper a useful metal? [3]

- Good conductor of heat & electricity - Easily bent, yet hard enough to make water pipes and tanks - Does not react with water

Where is copper extracted from?

Copper-rich ores

How is copper extracted from copper-rich ores?

By heating the ores with carbon in a furnance. This is known as smelting

What happens when the copper is smelted?

It is purified by electrolysis

How else can copper also be obtained? [2]

- From solutions of copper salts by electrolysis - By displacement using a scalp iron

What happens during electrolysis of copper?

Positive copper ions move towards the negatve electrode and form pure copper

The extensive mining of copper in the past, has meant that?

We're running out of copper-rich ores

What has occured to combat the decrease in copper-rich ores?

New methods have been developed to extract it from ores that contain less copper

What can copper be extracted from to combat the decrease of copper-rich ores? [2]

- Low grade ores - Contaminated land by biological methods

What is Phytomining?

A method that uses plants to absorb copper

What happens during Phytomining? [2]

- As plants grow, they absorb (and store) copper - The plants are then burned and the ash produced contains copper in a relatively high quantities

What is bioleaching?

Uses bacteria to extract metals from low-grade ores

What happens during bioleaching? [2]

- Solution containg bacteria is mixed with a low-grade ore - The bacteria converts the copper into a solution (leachate solution), from which the copper can easily be extracted

Is phytomining and bioleaching more enviromentally friendly than traditional mining methods?

Yes

What is a life cycle assessment used to assess?

The enviromental impact a product has over its whole lifetime.

What does life cycle assessment provide?

A way of comparing several alternative products to see which one causes the least damage to the enviroment

To carry out an LCA, what do scientists measure the impact of? [6]

- Extracting the raw material - Processing the raw materials - Manufacturing the product - How the product is use - How the product is transported - How the product is disposed of at the end of its life

Some aspects of the LCA are quite easy to {{c1::Quantify}}.

However, some aspsects of the LCA are difficult difficult to {{c1::quantify}} and involve {{c2::value}} judgements.

What is the danger of unscrupulos advertisers using shortened or abbreviated LCA's?

Can lead to misleading claims being made about a particular product

Are materials such as glass, metals and plastics important to our standard of living?

Yes

Why should materials such as glass, metals and plastics be reused and recycled whenever possible? [4]

- Save money and energy - Make sure natural resources are not used up unnecessarily - Reduce the amount of waste produced - Reduce damage to the enviroment caused by extraction

Metal, glass, building materials and plastics made from crude oil are produced from what?

Limited resources

Supplies of raw materials and the fossil fuels used to obtain them are often what?

Finite

What effects does the mining and quarrying processes that are used to extract raw materials, have on the enviroment?

Devasting enviromental impacts

Some objects such as plastic bags and glass bottles can be reused. Explain how? [3]

- Waste glass can be crushed melted and reused - Some waste plastic can be recycled to make fleece material - Metals can be recycled by melting them down and then making them into new objects

Does recycling generually use less energy than the initial extraction and production processes?

Yes

What is the effect of recycling? [2]

- Less fossil fuel are burnt and less greenhouse gases are released into the atmosphere. - It preserves reserves of raw materials for the future