Potable Water

Question 1

What is potable water?

Answer 1

Water that’s been treated or is safe for humans to drink

Question 2

How is pure water different from potable water?

Answer 2

Pure water contains zero dissolved substances whilst potable water does

Question 3

What is sterilisation?

Answer 3

To kill any harmful bacteria or microbes.

Question 4

How is water sterilised?

Theres three ways

Answer 4

By bubbling chlorine gas through it or by using ozone or ultraviolet light

Question 5

How do you test water?

Testing water for sodium and chloride atoms

Answer 5

1. Test the pH using pH meter
2. If pH is too high or too low neutralise it using titration
3. Test the water for any presence of sodium or chlorine

Question 6

How do you test for sodium in water?

Answer 6

You do a flame test.
If sodium ions are present the flame will turn yellow

Question 7

How do you test for chlorine in water

Answer 7

You add a few drops of dilute nitric acid followed by a few drops of silver nitrate solution, if chloride atoms are present a white precipitate will form.

Question 8

How do you distil water

Answer 8

1. Pour salty water into a distillation apparatus
2. Heat flask from below
3. Water will boil and form steam leaving any dissolved salts in the flask
4. Steam will condense back into liquid water and be collected as it runs out
5. Then retest the water’s pH

Question 9

How else can sea water be treated?
(Reverse osmosis)

Answer 9

The salty water is passed through a membrane that only allows water molecules to pass through
Really expensive

Question 10

How is desalination carried out

Answer 10

Can be dine by distillation or by processes that use membranes such as reverse osmosis. THESE PROCESSES REQIRE LARGE AMOUNTS KF ENERGY

Question 11

What is reverse osmosis

Answer 11

Sea water is passed through a membrane that only allows water molecules through
Requires high pressure to push the water through the membrane
The high pressure requires a lot of energy to produce