2.5 Using resources

What are Earth’s resources used for?

Warmth Shelter Food Transport

What do natural resources provide?

Food Timber Clothing Fuels

What are finite resources?

Resources that will run out

What are renewable resources?

Resources that are replenished quickly

What is sustainable development?

Meeting current needs without harming future generations

What is potable water?

Water safe to drink

Is potable water pure?

No it contains small amounts of dissolved substances

How is potable water produced in the UK?

Filtration and sterilisation

What does filtration remove?

Insoluble solids

What is used to sterilise water?

Chlorine Ozone UV light

What is desalination?

Removing salt from seawater

Name two desalination methods

Distillation Reverse osmosis

Why is desalination not widely used?

It is expensive

What is the first step in wastewater treatment?

Screening to remove large solids

What happens during sedimentation?

Solids sink to form sludge

What happens during anaerobic digestion?

Microbes break down waste

What is the final step in wastewater treatment?

Sterilisation

Why are alternative methods of extracting metals needed?

Ores are running out

What is phytomining?

Using plants to absorb metal compounds

What happens to plants in phytomining?

They are burned to produce ash

What is bioleaching?

Using bacteria to produce metal solutions

How can metals be extracted from solutions?

Displacement or electrolysis

What is a life cycle assessment?

Measuring environmental impact of a product

Name stages of LCA

Raw materials Manufacturing Use Disposal

Why is LCA not fully objective?

Some values are based on judgement

Name three ways to reduce resource use

Reduce Reuse Recycle

Why is recycling important?

Saves resources and energy

How can metals be recycled?

Melting and reforming

What is the Haber process?

Making ammonia from nitrogen and hydrogen

What are the raw materials for Haber process?

Nitrogen and hydrogen

What catalyst is used in the Haber process?

Iron

What conditions are used in the Haber process?

High temperature about 450C and high pressure about 200 atm

Is the Haber process reversible?

Yes

What happens to ammonia after formation?

It is cooled and removed

What happens to unreacted gases?

They are recycled

Why is high pressure used in Haber process?

Fewer gas molecules on product side

Why is low temperature not used in Haber process?

Rate would be too slow

What are NPK fertilisers?

Fertilisers containing nitrogen phosphorus potassium

Why are fertilisers used?

To increase crop yield

Where is potassium obtained from?

Mining

Why can phosphate rock not be used directly?

It is insoluble

How is phosphate rock made useful?

Reacted with acids to form soluble salts

What is produced when phosphate rock reacts with nitric acid?

Phosphoric acid and calcium nitrate

What is produced when reacted with sulfuric acid?

Single superphosphate

What is produced when reacted with phosphoric acid?

Triple superphosphate