Chemistry - USING RESOURCES (C10)

Finite & Renewable Resources -

What is a natural resource?

A resource that comes from the Earth, sea, / air, used for human needs.

Finite & Renewable Resources -

What is the difference between finite + renewable resources?

Finite resources will run out, renewable resources are replenished naturally.

Finite & Renewable Resources -

What is sustainable development?

Development that meets current needs w/out compromising future generations’ ability to meet theirs.

Water Treatment & Potable Water -

What is potable water?

Water that’s safe to drink, not necessarily pure (can contain dissolved substances).

Water Treatment & Potable Water -

How is potable water produced in the UK?

Choose a source (rivers, lakes etc.), filter to removed solids using mesh etc, sterilise using chlorine, ozone, or UV light.

Water Treatment & Potable Water -

What is desalination?

Removing salt from seawater by distillation / reverse osmosis.

Water Treatment & Potable Water -

Why is desalination not commonly used in the UK?

It requires a lot of energy + is expensive.

Waste Water Treatment -

What are the stages of sewage treatment?

Screening, sedimentation, aerobic digestion (biological treatment of effluent), anaerobic digestion (of sludge).

Waste Water Treatment -

What is the difference between effluent + sludge?

Effluent = liquid waste, sludge = solid material.

Corrosion & Protection -

What is corrosion?

The destruction of materials (usually metals) by chemical reactions w/ substance in the environment.

Corrosion & Protection -

What causes iron to rust?

Water + oxygen are both needed.

Corrosion & Protection -

What are two ways of preventing rusting?

Barrier methods (e.g. painting, oiling), sacrificial protection (e.g. galvanising w/ zinc).

Corrosion & Protection -

How does sacrificial protection work?

A more reactive metal (like zinc) corrodes instead of iron.

Alloys & Materials -

What is an alloy?

A mixture of metal w/ one / more other elements to improve properties.

Alloys & Materials -

Give an example of an alloy + its use.

Bronze = copper + tin (statues)

Brass = copper + zinc (instruments, taps)

Steel = iron + carbon (structures, tools)

Alloys & Materials -

What are ceramics?

Non-metallic, inorganic solids made by heating materials like clay.

Alloys & Materials -

What are composites?

Materials made from two / more materials combined for improved properties.

Life Cycle Assessment (LCA) -

What are the 4 stages of a life cycle assessment?

Raw material extraction, manufacture, use, disposal.

Life Cycle Assessment (LCA) -

Why are LCAs not always reliable?

They can be subjective + difficult to quantify (especially for environmental impacts).

Life Cycle Assessment (LCA) -

Why is reuse better than recycling?

Reuse often uses less energy + resources than recycling.

Reduce, Reuse, Recycle -

What are the benefits of recycling metals?

Saves energy, reduces pollution, conserves finite resources.

Reduce, Reuse, Recycle -

How is glass recycled?

Glass is crushed, melted, + reshaped into new products.

Pure vs Formulated Materials -

What is the difference between pure + formatted materials (in the context of resources)?

Pure material: made of one substance

Formulation: a mixture designed for a purpose (e.g. alloys, composites).