1. Solution of different salts
Food flavouring,
Make chlorine bleach
Sea water
contains
Solution of different salts
uses
Main components
Water
Sodium chloride
Impure powder
Pure crystal by by by
Distillation ( boils the sea water, then water turns to vapour, vapour is condensed back to liquid by cooling and is collected.
Filtration (remove insoluble impurities)
Natural evaporation
(large industry)
filtration
Evaporate some water so to form a saturated solution
Evaporate the solution until dryness. By Directly heating/heat with steam bath
Crystallization (cool at room temp slowly) -- as temp decreases, solubility of salt decreases, some salt cannot dissolve anymore, crystal is formed.
Dried the crystal by filter paper
Filtration (filter the crystal from the mixture )

2. Filtration of sea water.
glass rod
sea water
folded filter paper
Residue (sand / mud)
filter funnel
Filtrate (clear sea water)
stand
Filtration of sea water.

3. Performing evaporation in the school laboratory…
sea water
heat
steam
water
wire gauze
tripod
evaporating
basin
(a) Direct heating (b) Heating with a steam-bath

4. solution
saturated
with respect
to sodium
chloride
Filtered
sea water
sodium
chloride
crystals
sodium
chloride
crystals
more
concentrated
solution
water slowly evaporates at room temperature

5. Solution of different salts
Food flavouring,
Make chlorine bleach
Sea water
contains
Solution of different salts
uses
Main components
Water
Sodium chloride
Impure powder
Pure crystal by by by
Distillation ( boils the sea water, then water turns to vapour, vapour is condensed back to liquid by cooling and is collected.
Filtration (remove insoluble impurities)
Natural evaporation
(large industry)
filtration
Evaporate some water so to form a saturated solution
Evaporate the solution until dryness. By Directly heating/heat with steam bath
Crystallization (cool at room temp slowly) -- as temp decreases, solubility of salt decreases, some salt cannot dissolve anymore, crystal is formed.
Dried the crystal by filter paper
Filtration (filter the crystal from the mixture )

6. Distillation using simple apparatus. thermometer clamp delivery tube
end of delivery
tube should be
above the distillate
delivery tube
receiver test tube
pure water
(distillate)
heat
boiling tube
clamp
thermometer
water (cooling
agent)
sea water
anti-bumping granule
(ensure smooth boiling)

7. Distillation using ‘Quickfit’ apparatus. thermometer
heat
thermometer
pear-shaped
flask
anti-bumping
granule
solution
water
condenser
receiver
adaptor
test tube
(as receiver)
cold water in
(from tap)
water out (to sink)
thermometer bulb
distillate
cold water

8. Solution of different salts
Sea water
Boil at sharp 100oC
(boiling point test)
Pure water
contains
Solution of different salts
Main components
Water
Sodium chloride
Sodium ions
Chloride ions
(in solution form)
Tested by
Tested by
Anhydrous copper(II) sulphate
Dry cobalt chloride paper
Flame test
Tested by
Silver nitrate solution
White to blue
Blue to pink
Excess dilute nitric acid
White precipitate fomed

9. Testing the presence of sodium ions in sodium chloride
By flame test

10. Step 2
Dip the wire into a crushed sample (or solution) of the salt to be tested.
non-luminous flame
sample of the salt to be tested

11. Heat the end of the wire strongly in a non- luminous flame.
Step 3
Heat the end of the wire strongly in a non- luminous flame.
flame colour due to metal ions

12. The results of flame test of some metal compounds are as follows:
Compound containing
Flame colour
Potassium ion
Lilac
Sodium ion
Brilliant golden yellow
Calcium ion
Brick-red
Copper(II) ion
Bluish green

13. Potassium nitrate
Calcium chloride
Copper(II) sulphate
Sodium carbonate

14. Moisten a clean platinum wire with concentrated hydrochloric acid.
Step 1
Moisten a clean platinum wire with concentrated hydrochloric acid.
platinum
wire
concentrated
hydrochloric
acid

15. Test for chloride ions
white precipitate
of silver chloride
sea water
add silver nitrate solution, followed by
excess dilute nitric acid
Fig Silver nitrate test for the presence of chloride ions.

16. + + sodium chloride silver chloride silver nitrate sodium nitrate
(white precipitate)
silver chloride +
silver nitrate +
sodium nitrate