SC2e - drinking water Flashcards Preview

Chemistry Gcse > SC2e - drinking water > Flashcards

Flashcards in SC2e - drinking water Deck (10)
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1
Q

What percentage of the earth’s water is in the ocean?

A

97%

2
Q

What is desalination?

A

Producing pure water from seawater

3
Q

Why is water used form chemical analysis pure?

A

So there are no incorrect results

4
Q

Where does drinking water usually come from in the uk?

A

Rivers, lakes or aquifers and is then usually softened in reservoirs

5
Q

What does fresh water that comes from lakes, rivers and aquifers usually contain?

A
  • Objects like leaves and twigs
  • small insoluble particles like grit
  • soluble substances like pesticides, salts and microorganisms that could be harmful to health
6
Q

How is desalination usually achieved?

A

Simple distillation

7
Q

What is step one of water purification?

A

Coarse filtration to get out large sediments in the water

8
Q

What is step two of water purification?

A

Sedimentation where dirt particles in water clump together and sink to the bottom

9
Q

What is step three of water purification?

A

Fine filtration where any remaining dirt particles get sprayed through a filter of sand and gravel

10
Q

What is step four of water purification?

A

Chlorination which is when a small amount of chlorine gets put through the water to kill any bacteria and microbes