Purifying And Testing Water Flashcards Preview

Chemistry Module 4 > Purifying And Testing Water > Flashcards

Flashcards in Purifying And Testing Water Deck (15):
1

Explain why water is an important resources for many important industrial chemical processes

Because the industry uses large amounts of water for cooling, as a solvent and as a cheap raw material

2

List some of the pollutants that may be found in domestic water supplies

Nitrate residues
Lead compounds
Pesticide residues

3

List the type of substances present in water before it is purified

Dissolved salts and minerals
Microbes
Pollutants
Insoluble materials

4

What is the purpose of chlorination?

Kills microbes in water

5

Recall that barium chloride solution is used to test dir sulfate ions

Gives a white precipitate

6

Recall that silver nitrate solution is used to test for halide ions

Chloride ions gives a white precipitate
Bromide ions give a cream precipitate
Iodide ions give a pale yellow precipitate

7

Explain why drinking water may contain some of the pollutants nelow:
- Nitrate
- lead compounds
- pesticide

- nitrates - from the run-off of fertilisers
- lead compounds- from old pipes in plumbing
- pesticides - from spraying crops near to the water supply

8

Describe the water purification process

- Sedimentation - the water settles to allow the insoluble particles to sink
- filtration - to remove very fine particles
- chlorination - to kill the microorganisms in water

9

Word equation for sodium sulfate and barium chloride

Sodium sulfate + barium chloride ->sodium chloride + barium sulfate

10

Word equation for sodium chloride and silver nitrate

Sodium chloride + silver nitrate -> silver chloride + sodium nitrate

11

Word equation for sodium bromide and silver nitrate

Sodium bromide + silver nitrate -> silver bromide + sodium nitrate

12

Word equation for sodium iodide and silver nitrate

Sodium iodide + silver nitrate -> silver iodide + sodium nitrate

13

Explain the disadvantages of using distillation of sea water to make large quantities of fresh water

Lost of energy so is costly
Expensive equipment

14

Recall different types of water resources found in the united kingdom

Lakes
Rivers
Aquifers
Reservoirs

15

Why aren't all soluble substances are removed?

They are not a danger and may improve the taste of the water