1. ATMOSPHERE OCEAN ROCKS & MINERALS
F4 CHEMISTRY
ATMOSPHERE
OCEAN
ROCKS & MINERALS

2. PLANET EARTH (matter) GASES IN THE AIR COMPOUNDS IN SEA WATER
COMPOUNDS OF METALS

3. MATTER (substance) Gas Solid Liquid (solution) ATMOSPHERE EARTH OCEAN\

4. THE ATMOSPHERE
Atmosphere
AIR
Earth

5. AIR (composition) NITROGEN (78%) OXYGEN (21%) NOBLE GASES (1%)
CARBON DIOXIDE ( %)
WATER VAPOUR
OTHERS

6. AIR (separating gases)
Liquefaction of air
AIR (g) → AIR (l)
Fractional distillation of liquid air (Fractionating column)
Nitrogen (g) (bp=-196oC)
AIR (l)
Oxygen (g) (bp=-183oC)

7. TEST FOR GASES OXYGEN NITROGEN CARBON DIOXIDE
RELIGHTS A GLOWING SPLINT
NITROGEN
NO SIMPLE TEST
CARBON DIOXIDE
TURNS LIME WATER TO MILKY
Lime water (calcium hydroxide solution)
Milky substance (calcium carbonate)

8. WORD EQUATION CARBON DIOXIDE turns LIME WATER to milky
Carbon + Calcium → Calcium + water
dioxide hydroxide carbonate
(g) (aq) (s) (l)

9. TEST FOR GASES (cont.) CARBON DIOXIDE (excess) CHLORINE
MILKY SOLUTION TURNS COLOURLESS
Colourless solution (calcium hydrogencarbonate solution)
CHLORINE
Bleaches wet litmus paper

10. OCEAN OCEAN - SEA WATER SEA WATER - AQUEOUS SOLUTION
SEA WATER CONTAINS
WATER (96.5%)
DISSOLVED SALTS (2.5%)
Mostly common salt (sodium chloride)
OTHERS(includes dissolved gases) (1%)

11. Obtain common salt from Sea water
FILTRATION
RESIDUE – mud, sand, solid particles
FILTRATE – sea water
EVAPORATION of the filtrate
Dilute solution → Concentrated solution → Saturated solution
CRYSTALLIZATION
Cool slowly – to obtain large crystals of Salt (NaCl)
Filtration – to obtain Salt

12. Obtain pure water from Sea water
DISTILLATION
Boiling
Water (l) → Water (g)
(water vapour)
Condensing
Water (g) → Water (l)
Distillate
- pure water / distilled water

13. TEST FOR COMMON SALT SALT IS AN IONIC COMPOUND CATION (from metals)
Test – FLAME TEST
ANION (from non-metals)
Test – Chemical Test

14. FLAME TEST FOR CATIONS Nichrome wire Concentrated hydrochloric acid
Bunsen burner
Colour of flame
Potassium compound
Sodium compound
Calcium compound

15. TEST FOR ANION (chloride)
Silver nitrate solution & dilute nitric acid
Add to a solution of chloride
White precipitate appear
White precipitate is SILVER CHLORIDE
Word equation:

16. TEST FOR ANION (sulphate)
Barium chloride solution & dilute hydrochloric acid
Add to a solution of sulphate
White precipitate appear
White precipitate is BARIUM SULPHATE
Word equation:

17. TEST FOR ANION (carbonate)
Dilute hydrochloric acid
Add to a solution of carbonate
Effervescence
Colourless gas is CARBON DIOXIDE
Word equation:

18. TEST FOR WATER Dry cobalt(II) chloride paper (blue)
Water turns blue cobalt(II) chloride paper pink.

19. ELEMENTS OF WATER COMPOUND → ELEMENTS Word equation
WATER → OXYGEN + HYDROGEN
(Compound) (Elements of water)
ELECTRICITY is required
SOURCE OF ELECTRICITY (CELL)
POSITIVE ELECTRODE (+)
NEGATIVE ELECTRODE (-)
The process is ELECTROLYSIS OF WATER

20. Dissolved salts in Sea water
Sodium chloride (NaCl)
Magnesium chloride (MgCl2)
Potassium sulphate (K2SO4)
Calcium chloride (CaCl2)
Dissolved ions
(Dissolved ions of Na+, Cl-, Mg2+, SO42-, K+, Ca2+)

21. Electrolysis of Sea water
Sea water is a mixture
Water + dissolved Salts
Substances from electrolysis of sea water using carbon electrodes:
Hydrogen (at the negative electrode)
Chlorine (at the positive electrode)
Sodium hydroxide (in the solution)

22. EARTH’S CRUST (Minerals)
ROCK is a mixture of MINERALS
MINERALS
Compounds
Elements
Gold
Silver
Compounds of metals
Compounds of non-metals
Al2O3
CaCO3
SiO2

23. ORES ORE Examples of Ore Rock containing compounds of metals
Bauxite (aluminium ore)
Haematite (iron ore)
Cinnabar (mercury ore)

24. EXTRACTION OF METALS FROM ORES
Physical separation
Heating of ore
Heating the ore with carbon
Electrolysis of molten ore

25. CHALK, LIMESTONE, MARBLE
Calcium carbonate exists in 3 forms:
Chalk
Limestone
Marble
Formation of chalk
Skeleton or shells of dead sea animals
High pressure or temperature
Long time

26. Investigating Calcium carbonate
Action of heat
Calcium Calcium + carbon
carbonate oxide dioxide
Action of dilute hydrochloric acid
Effervescence
Calcium chloride, carbon dioxide, water
Action of water
Insoluble in water

27. LIMESTONE and related compounds
Calcium carbonate ( formula)
QUICKLIME
Calcium oxide ( formula)
SLAKED LIME
Calcium hydroxide ( formula)
LIMEWATER
Saturated solution of calcium hydroxide (formula )

28. Further reactions
Calcium oxide reacts with water to form calcium hydroxide
Calcium hydroxide is slightly soluble in water
Limewater is a saturated solution of calcium hydroxide
Limewater can be used to test for carbon dioxide gas
(The milky substance is calcium carbonate)

29. EROSION Erosion is a complicated process Causes of erosion
Broken down into smaller pieces
Changed into other material
Lost of surface material
Causes of erosion
Heat
Rain (acid rain)
Wind, running water, gravity

30. FORMATION OF LIMESTONE CAVES
Heat decomposes limestone
forms calcium oxide and carbon dioxide
Acid rain reacts with limestone
forms salt and carbon dioxide
(carbon dioxide dissolves in rain water to form carbonic acid)
Limestone is slightly soluble in water