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Combined Science: Chemistry

GCSE · Edexcel · foundation

QuestionsFlashcards

Obtaining & Using Metals
Reversible Reactions & Equilibria
- Reversible Reactions & Equilibrium
  3
- The Haber Process
  4

Group 1
- Group 1 (Alkali Metals)
  4
- Group 1: Reactivity & Electronic Configurations
  4
Group 7
Group 0

Purifying Water Flashcards

All 7 cards in this deck

What is potable water?: Water that is safe to drink; it may still contain dissolved impurities, as long as they are harmless.
In what order are the three main processes used to make waste or ground water potable?: Sedimentation → filtration → chlorination.
Why is chlorine added to water during water treatment?: To kill bacteria / microorganisms.
Why is water filtered during water treatment?: To remove insoluble substances / solids.
How is sea water made potable?: By (simple) distillation — the water is boiled off and the vapour condensed, leaving the dissolved salts behind.
Why is tap water not suitable for use in chemical analysis?: It is not pure — dissolved ions (e.g. calcium or chloride ions) are present and would interfere with the test.
What happens during sedimentation in water treatment?: The water is left to stand so insoluble particles sink to the bottom. Chemicals may also be added so that very fine particles stick together into bigger lumps, which then sink too.