Using Resources Flashcards by Dhruv Bhanderi

Renewable resources

How well did you know this?

Not at all

Perfectly

Finite resources

How well did you know this?

Not at all

Perfectly

Potable water

Water that is safe to drink

Contains dissolved substances such as salts and microbes

How well did you know this?

Not at all

Perfectly

Pure water

Has no dissolved salts

How well did you know this?

Not at all

Perfectly

Sterilising agents

Chlorine

Ozone

Ultraviolet light

How well did you know this?

Not at all

Perfectly

Desalination

Removing salt from a solvent

How well did you know this?

Not at all

Perfectly

Desalination - distillation

Sea water is heated until it boils

The salt remains in the liquid, and the steam is pure water

The steam is cooled and condensed to make potable water

How well did you know this?

Not at all

Perfectly

Disadvantages of distillation

Requires a lot of energy to heat up and condense

The waste water is very salty and hard to dispose of in a environmentally friendly way

How well did you know this?

Not at all

Perfectly

Desalination - reverse osmosis

Water is put under high pressure and passed through a membrane which has tiny pores (holes) in it

The pores allow water molecules through but prevents most ions and molecules from passing through

How well did you know this?

Not at all

Perfectly

Disadvantages of reverse osmosis

Requires expensive membranes

Produces a large volume of waste water = low efficiency

How well did you know this?

Not at all

Perfectly

Waste water treatment

Screening - to remove large particles, e.g. grit

Sedimentation - solids sink to form sewage sludge and effluent (liquid) which remains on top

Sludge is dried and anaerobically digested by microbes, removing organic matter

The dried sludge is used as fertilisers and also produces biogas which generates electricity

Effluent is aerobically digested by microbes, removing organic matter and harmful microbes

How well did you know this?

Not at all

Perfectly

Analysis and purification of water required practical

For each sample of water, test the pH using a universal indicator

For each sample of water, pour 50 cm3 into a clean pre-weighed evaporating basin

Heat gently over a Bunsen burner, tripod and gauze until no liquid remains

Allow to cool, then weigh the evaporating basin again and calculate the mass of the solid that remains in the evaporating basin

How well did you know this?

Not at all

Perfectly

Extracting copper from ores - smelting

A method of producing refined goods using heats

Advantage - high concentrations of Cu can be extracted

Disadvantages - high amounts of energy needed = expensive, charcoal produces carbon dioxide

How well did you know this?

Not at all

Perfectly

Extracting copper from ores - bioleaching

Bacteria absorbs copper compounds, producing solutions called leachates

Advantage - very clean method

Disadvantage - only works with small amount of copper

How well did you know this?

Not at all

Perfectly

Extracting copper from ores - phytomining

Crops are planted onto the soil with a small amount of copper, the plants absorb the copper via the roots, then the plant is burnt to produce ash with copper ions

Advantage - plants are renewable

Disadvantage - produces carbon dioxide

How well did you know this?

Not at all

Perfectly

Extracting copper from ores - electrolysis

When compounds are broken down into smaller substances

Disadvantages - uses a lot of electricity = expensive

How well did you know this?

Not at all

Perfectly

Life cycle assessments (LCAs)

They assess the environmental impact of products in each of these stages

extracting and processing raw materials
manufacturing and packaging
use and operation during its lifetime
disposal at the end of its useful life, including transport and distribution at each stage

How well did you know this?

Not at all

Perfectly

Corrosion

The destruction of materials by chemical reactions with substances in the environment

E.g. rusting (air and water is needed)

Preventing corrosion

Corrosion can be prevented by applying a coating that acts as a barrier, such as greasing, painting or electroplating

Aluminium has an oxide coating that protects the metal from further corrosion

Alloys

A mixture of two or more elements, at least one of which is a metal

Bronze

An alloy of copper and tin

Used as propellers for ships, bells

Brass

An alloy of copper and zinc

Used for coins, musical instruments

Gold

An alloy with silver, copper and zinc

Used for jewellery

Steel

An alloy of iron that contain specific amounts of carbon and other metals

High carbon steel is strong but brittle

Low carbon steel is softer and more easily shaped

Stainless steel

An alloy containing chromium and nickel is hard and resistant to corrosion

Production of glass

Made by heating a mixture of sand, sodium carbonate and limestone Borosilicate glass, made from sand and boron trioxide, melts at higher temperatures than soda-lime glass

Production of ceramics

Made by shaping wet clay and then heating it in a furnace

Low density poly(ethene) - LDPE

Flexible, unreactive, can be made into films Most carrier bags, bubble wrap Random arrangement of molecules

High density poly(ethene) - HDPE

Strong, flexible, resists shattering, resists chemical attack Plastic bottles, pipes, buckets More uniformed arranged of molecules

Thermosoftening polymers

Melt when they are heated Thermosoftening plastics do not have covalent bonds between neighbouring polymer molecules, so the molecules can move over each other when heated and the plastic melts Used in many everyday plastics

Thermosetting plastics

Do not melt when heated They tend to char and burn when heated, but they are resistant to much higher temperatures than thermosoftening plastics Used to make electrical plugs

Composite materials

Material made from two or more different materials with contrasting properties

Matrix

The substance that binds the reinforcement together in a composite material

Reinforcement

Fibres or other material that make up the bulk of a composite material.

Reinforced concrete

A composite material that is reinforced by steel and has a matrix of concrete

Fibreglass

A composite material that is reinforced by glass fibres and has a matrix of polymer resin

Carbon fibre reinforced polymer

A composite material that is reinforced by carbon fibre chips and has a matrix of polymer resin

Chipboard

A composite material that is reinforced by wood chips and has a matrix of resin glue

Haber process

Used to manufacture ammonia, which can be used to produce nitrogen-based fertilisers The raw materials for the Haber process are nitrogen and hydrogen

Source for nitrogen

Nitrogen is obtained from the air

Source for hydrogen

Hydrogen is obtained by reacting natural gas (mostly methane) with steam, or from cracking oil fractions

Process of the Haber process

The purified gases are passed over a catalyst of iron at a high temperature (about 450°C) and a high pressure (about 200 atmospheres) Some of the hydrogen and nitrogen react to form ammonia The reaction is reversible so some of the ammonia produced breaks down into nitrogen and hydrogen On cooling, the ammonia liquefies and is removed The remaining hydrogen and nitrogen are recycled

NPK fertilisers

Compounds of nitrogen, phosphorus and potassium are used as fertilisers to improve agricultural productivity NPK fertilisers are formulations of various salts containing appropriate percentages of the elements

Treatment of phosphate rock

Ammonia + nitric acid → ammonium nitrate Ammonium hydroxide + nitric acid → ammonium nitrate + water Ammonia + sulfuric acid → ammonium sulfate Ammonium hydroxide + sulfuric acid → ammonium sulfate + water