Saturday, 11 June 2011
Wednesday, 1 June 2011
Natural Fuel Resources and Their Importance
Klik foto untuk lebih jelasUses of petroleum
Petroleum, natural gas, coal and wood are natural fuel resources found in the Earth’s crust which are non-renewable
Petroleum is usually obtained together with natural gas
Petroleum can be separated to several fraction by distillation
The higher the boiling point of the fraction
(a) the darker its colour
(b) the higher its viscosity
(c) the harder it is to burn
(d) produced more soot in flame
All petroleum fractions do not dissolve in water
Natural gas can be stored under high pressure
in tanks for easy storage and transport
About 90% of natural gas is methane while the balance is made up of hydrocarbons such as ethane, butane and propane
Coal is a black solid that contains mainly carbon and small amounts of hydrogen, oxygen, nitrogen and sulphur
Saturday, 30 April 2011
Saturday, 23 April 2011
Land and its Resources 01 Tanah dan Sumbernya
The properties of mineral. Different minerals have different characteristics. Mineral possess different characteristicc in term of:
1. Hardness
2. Solubility in water
3. Effect of Heat
HARDNESS
Hardness of mineral refers to the resistance offered by the mineral on being scratched.
The hardness of a mineral is measured In Mohs unit.
Most mineral are hard. This mineral can only be scratched by hard objects such as knives.
Nevertheless, hard mineral can scratch softer minerals.
All mineral made up of….Carbonate….Oxide….Sulphide compound are HARD
(e.g Iron oxide, Calcium carbonate, Zinc sulphide)
Diamond is the HARD mineral, while Talc is the softest mineral
Most minerals exists in the form of compounds like
1. oxides,
2. sulphides
3. Carbonates
Oxides, sulphides and carbonates are usually hard minerals.
SOLUBILITY
All minerals of METAL OXIDES, SULPHIDES, CARBONATES are insoluble /does not dissolve in water
EXCEPT minerals of metallic Potassium and sodium compound.
EFFECT OF HEAT
Metal Carbonate
All metal carbonate DECOMPOSE when HEATED.
EXCEPT Potassium carbonate, Sodium carbonate because both of the metal are very stable.
The heathing of metal carbonate form Metal oxides and carbon dioxide gas.
Silicon Silikon
Silicon Compounds
Silicon is the second most abundant element in the Earth’s crust
Silicon usually exist in the form of
1.Silica (Silicon. Oxygen) or (silicon dioxide)
2.silicates (Silicon. Oxygen.Metal)
Silica
The chemical compound silicon dioxide also known as silica.
Silicon + Oxygen -------- Silicon dioxide (silica)
Example of silica are sand, quartz and flint.
Silicate
Silicate is the chemical compound consist of silicon, oxygen and metal
Silicon + Oxygen + Metal-------------Silicate
Example of silicate are mica, ruby and jade
Pure silicon is used to make electronic chips also known as silicon chips
Properties of silicon compounds
1.Silicon compounds are very stable
2.Silicon compounds
do not dissolve in water
do not react with acids
do not decompose when heated
Uses of silicon compounds
Mica
Used in heating appliances as electrical insulators
Quartz
Manufacture of glass
Sand
Manufacture of glass
To make container
To make insulators
Asbestos
Used as heat insulators in fire-proof clothing worn by fire fighters
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Calcium Carbonate Kalsium Karbonat
CARBONATE is a Compounds( Carbon & Oxygen).
Calcium carbonate is a Compounds( Calcium & Carbon & Oxygen).
Calcium carbonate is the chemical compound consist of calcium, carbon and oxygen.
Calcium carbonate exists in several forms like limestone, marble, calcite and chalk
Is a white hard solid compound do not dissolve in water
Reacts with acids to form salt, water and releases carbon dioxide
Calcium carbonate + Acid -------- Calcium salt + Carbon dioxide + Water
Calcium carbonate will decompose into calcium oxide and releases carbon dioxide when heated
Calcium carbonate ---heated----- Calcium oxide + Carbon dioxide
Calcium Carbonate Kalsium Karbonat
When calcium carbonate (limestone) is heated over high heat, it will decomposes into calcium oxide (quicklime) and releases carbon dioxide.
Calcium carbonate ------- Calcium oxide + Carbon dioxide.
Calcium oxide reacts with water to form calcium hydroxide (slaked lime)
Calcium oxide + Water ------ Calcium hydroxide(Slaked lime)
Slaked lime dissolve In water to form calcium hydroxide solution (lime water)
Solid calcium hydroxide + Water ------ Calcium hydroxide solution(Lime water).
