September 12, 2010

raya...raya...raya...!!!!






seronok gler rye taun nih...
best gilerrr arhhhh!!!!

nk tw x sbb ap????
taun ni rye meriah coz abg ngn akk ak sume rye kat uma...
da 2 taun abg ak yg kat mesir tu x rye sesme ngn kitorg...
akk ak yg kat jordan tu pon sme....

cume yg xde abg ipar ak je..
dye kne kje tym rye....sdey an!!!
yg blk cume akak ngn ank dye...

tu pon dah meriah sgt da...
ak nk letak gmba tp xmsuk pc ag....
nnt da msuk ak letak laa...

ok...setakat nih....daaaaaaaaaa~~

September 10, 2010

selamat hari raya~~



kat sini...aja nk mintak maaf atas segala salah dan silap....

kita berdoa la semoga ramadan yang berlalu ini bukanlah ramadan lita yang terakhir.....

...............selamat hari raya maaf zahir dan batin......................

(",)

September 9, 2010

carbon compound [part 9]....final

SPM Form 5 – Terminology and Concepts: Carbon Compounds (Part 9 – Final)

Polymers

1. Polymer – many small units (monomers) joining together to formed large molecule.

2. Polymer can be classified into two groups:

  • synthetic polymers / man-made polymers (polythene; PVC – polyvinyl chloride; artificial silk; and polypropene)
  • natural polymers (natural rubber; starch; cellulose; and proteins)

3. Natural polymer: Carbohydrates (polysaccharides) (starch, glycogen and cellulose)

  • General formula: Cx(H2O)y with the ratio of H:O = 2:1
  • Carbohydrates have cyclic structure.
  • Monomer: glucose (C6H12H6)
  • Reaction to form polymer: condensation reaction (- H2O)

4. Natural polymer: Protein (polypeptide)

  • Protein consists of carbon, hydrogen, oxygen and nitrogen (some have sulphur, phosphorus and other elements)
  • Monomer: amino acids
  • Amino acids have two functional group which are carboxyl group (-COOH) and amino group (-NH2)
  • Reaction to form polymer: condensation reaction (- H2O)

5. Natural polymer: Natural rubber

  • Extracted from the latex of rubber tree (Hevea brasiliensis) which the tree originates from Brazil.
  • A molecule of rubber contains 5000 isoprene units.
  • Monomer: isoprene, C3H8 or 2-methylbuta-1,3-diene.
  • Reaction to form polymer: additional polymerisation (one of the double bond in isoprene becomes single bond)

6. Structure of rubber molecule

  • Latex is colloid (35% rubber particles and 65% water).
  • Rubber particle contains rubber molecules which are wrapped by a layer of negatively-charged protein membrane. Same charge of rubber molecules repels each other. This prevent rubber from coagulate.

7. Coagulation process of latex

The process for the coagulation of latex is summarised as:

  1. Acid (H+) can neutralise the negatively-charged protein membrane. Example of acid: formic acid, methanoic acid, suphuric acid and hydrochloric acid.
  2. The rubber molecules will collide after the protein membrane is broken.
  3. Rubber molecules (polymers) are set free
  4. Rubber molecules combine with one another (coagulation).

8. Natural coagulation process of latex

For the natural coagulation of latex:

  1. Latex is exposed to air without adding acid (duration – overnight).
  2. Coagulation process occurs in slower pace due to the bacteria (microorganism) action which produce acid)

9. Prevent coagulation process of latex

The following are latex coagulation prevention method:

  1. Alkaline / Basic solution is added to the latex. Example: ammonia (NH3).
  2. Positively-charged hydrogen ion / H+ produced by bacteria can be neutralised by negatively-charged hydroxide ion / OH- from ammonia solution.

10. Properties of natural rubber

  • elastic
  • cannot withstand heat (become sticky and soft – above 50°C; decompose – above 200°C; hard and brittle – cooled)
  • easily oxidised (present of C=C)
  • insoluble in water (due to the long hydrocarbon chains)
  • soluble in organic solvent (propanone, benzene, petrol etc.)

11. Vulcanisation of rubber

Vulcanisation – process of hardening rubber and increases rubber elasticity by heating it with sulphur or sulphur compounds.

Methods:

  • heating natural rubber with sulphur at 140°C using zinc oxide as catalyst or
  • dipping natural rubber in a solution of disulphur dichloride (S2Cl2) in methylbenzene.

12. Properties of vulcanisation of rubber

  • The sulphur atoms are added to double bonds in the natural rubber molecules to form disulphide linkages (-C-S-S-C-) / sulphur cross-links between the long polymer chains. Therefore, vulcanised rubber is more elastics and stronger.
  • This increases the molecular size and the intermolecular forces of attraction between rubber molecules. Therefore, vulcanised rubber is more resistant to heat (does not become soft and sticky when hot).
  • This also reduces the number of carbon-carbon double bonds in rubber molecules. Therefore, vulcanised rubber is more resistant to oxygen, ozone, sunlight and other chemicals.

13. Comparison between the properties of vulcanised rubber and unvulcanised rubber

Properties Vulcanised rubber Unvulcanised rubber
Double bonds Decreases (formation of sulphur cross-links) More number of double bonds
Melting point High (presence of sulphur) Low
Elasticity More elastic (sulphur cross-links prevents the polymer chain or rubber from slipping past. Less elastics
Strength and hardness Strong and hard (depends on degree of vulcanisation) Weak and soft (polymer chain of rubber will break when rubber is over stretched.
Resistant to heat Resistant to heat Poor resistant to heat
Oxidation Resistant to oxidation (reduction of number of double bonds per rubber molecule) Easily oxidised by oxygen, UV light (presence of many double bonds per rubber molecules)

14. R & D of rubber

  • RRIM – Rubber Research Institute of Malaysia
  • MRB – Malaysian Rubber Board
  • Rubber Technology Centre
  • Various local higher institutions of learning

..........got it from http://berryberryeasy.com/........

carbon compound [part 8]

SPM Form 5 – Terminology and Concepts: Carbon Compounds (Part 8 )

Non-Hydrocarbon – Fats

1. Fatrs are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.

2. Fats (lipids / triglycerides) are belonging to the group in ester.

3. Natural esters are formed from glycerol and fatty acids.

Name of fat Molecular formula of ester Types of

fatty acids

Lauric acid* CH3(CH2)10COOH Saturated
Palmitic acid* CH3(CH2)14COOH Saturated
Stearic acid* CH3(CH2)16COOH Saturated
Oleic oxide ** CH3(CH2)7CH=CH(CH2)7COOH Unsaturated
Linoleic acid*** CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH Unsaturated
Linolenic acid*** CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH Unsaturated

* Saturated: C-C single bonds

** Unsaturated (monounsaturated): C=C double bonds

*** Unsaturated (polyunsaturated): C=C double bonds

4. Animal fats have higher percentage of saturated fatty acids than unsaturated fatty acids.

5. Plant oils have higher percentage of unsaturated fatty acids than saturated fatty acids.

6. Physical properties of fats


Saturated Unsaturated
Types of fatty acids C-C single bonds C=C double bonds
Bonding single double
Melting point higher lower
Sources animals plants
Cholesterol high low
State at room temperature solid liquid

Fats (animal) in general are solids at room temperature and acted as:

  • thermal insulator
  • protective cushion to protect the vital organ
  • provide energy and stored in body
  • carry Vitamin A, D, E, K (insoluble in water)
  • Example: butter, fish oil (liquid in room temperature)
  • Fats (plant) are called oils. Oils are liquids at room temperature.
  • Example: olive oil, peanut oil, palm oil and bran oil

7. Chemical properties of fats

  • Unsaturated fats can be converted into saturated fats by hydrogenation (additional reaction) in 200°C and 4 atm in the presence of nickel catalyst.
  • Example: production of margarine from sunflower oil of palm oil.

8. Effect of fats

Fatty food produce high energy but high consumption of fatty food will results:

  • obesity
  • raise the level of cholesterol
  • deposition will cause block the flow of blood which lead to stroke and heart attack.

9. Palm oil

  • It is extracted from fresh oil palm fruits.
  • Palm oil – extracted from the pulp of the fruits.

Steps in extraction of palm oil:

  1. sterilising (oil palm fruit)
  2. stripping
  3. digestion (crushing the husk and fruit and separate the oil by heating)
  4. squeezed out the oil
  5. extraction (separate the oil from water)
  6. purification the oil (palm oil is treated with phosphoric acid and then steam is passed through to separate the acid)
  7. vacuum

Palm kernel oil – extracted from the kernel or seed.

Steps in extraction of palm oil:

  1. sterilising (oil palm fruit)
  2. stripping
  3. crushing the husk and fruit
  4. extracting kernel oil
  5. purification (purify the oil from kernel)

Goodness in palm oil:

  • higher proportion of unsaturated fats.
  • easy to digest and absorb.
  • rich in vitamin A (carotenoid)
  • rich in vitamin E (tocophenols and tocotrienols)
  • resist oxidation in high temperature.

..........got it from http://berryberryeasy.com/........

carbon compound [part 7]

SPM Form 5 – Terminology and Concepts: Carbon Compounds (Part 7)

Non-Hydrocarbon – Esters

1. General formula: CnH2n+1COOCmH2m+1
Where n = 0, 1, 2, 3 … and m = 1, 2, 3 … (n and m = number of carbon)
R
COOR‘ where R and R‘ represented the same or different alkyl groups.

2. Esters are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.

3. The functional group in ester is carboxylate group, – COO -.
CnH2n+1COOH + CmH2m+1OH –> CnH2n+1COOCmH2m+1 + H2O

  • First part: taken from the alcohol (alkyl group)
  • Second part: taken from the carboxylic acid (-oic to -oate)
Name of ester Molecular formula of ester Prepared from
Ethyl methanoate HCOOC2H5 Ethanol + Methanoic acid
Methyl ethanoate CH3COOCH3 Methanol + Ethanoic acid
Propyl ethanoate CH3COOC3H7 Propanol + Ethanoic acid
Ethyl propanoate C2H5COOC2H5 Ethanol + Propanoic acid

4. Physical properties of ester

Name Odour
3-metylbutyl acetate Banana
Ethyl butanoate Pineapple
Octyl ethanoate Orange
Isoamyl isovalerate Apple
  • Simple esters are colourless liquid and are found in fruits and flowers.
  • Esters have sweet pleasant smell.
  • Esters are covalent compounds.
  • Esters are insoluble in water but soluble in organic solvent.
  • Esters are less dense than water.
  • Esters are neutral and cannot conduct electricity.
  • The higher and more complex esters have higher boiling points and less volatile.

Natural sources:

  • Vegetable oils (palm oil) and liquids esters can be found in plants derived from glycerol and fatty acids.
  • Fats are solid esters (milk fat) derived from glycerol and fatty acids.
  • Waxes (beewax) are solid ester derived from long-chain fatty acids and long-chain alcohols.

5. Uses of Esters

  • Preparation of cosmetics and perfumes (esters are volatile and have sweet smell).
  • Synthetic esters used as food additives (artificial flavour).
  • Natural esters serves as storage reserve of energy in living things.
  • In plant, wax (esters) helps to prevent dehydration and attack of microorganisms.
  • Esters used as solvents for glue and varnishes.
  • Esters used to make plastics softer.
  • Esters used to produce polyester (threads and synthetics fabrics)
  • Esters used to produce soap and detergents.

..........got it from http://berryberryeasy.com/........

carbon compound [part 6]

PM Form 5 – Terminology and Concepts: Carbon Compounds

Non-Hydrocarbon – Carboxylic Acids

1. General formula: CnH2n+1COOH

  • Where n = 0, 1, 2, 3 … (n = number of carbon)

2. Carboxylic acids are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.

3. The functional group in alcohols is carboxyl group, – COOH.

Name of carboxylic acids Molecular formula of alcohol
Methanoic acid(Formic acid) HCOOH
Ethanoic acid(Acetic acid) CH3COOH
Propanoic acid C2H5COOH
Butanoic acid C3H7COH

4. Physical properties of carboxylic acid

Name Molecularformula Boiling point (°C)
Methanoic acid(Formic acid) HCOOH 101
Ethanoic acid(Acetic acid) CH3COOH 118
Propanoic acid C2H5COOH 141
Butanoic acid C3H7COH 164
  • Solubility in water – generally in carboxylic acid (the less than four carbon atoms) are very soluble in water and ionise partially to form weak .
  • Density of carboxylic acid – density of carboxylic acid increases due to the increases in the number of carbon atoms in a molecule.
  • Boiling points – all carboxylic acid in general have relatively high boiling points than the corresponding alkanes. This is due to the presence of carboxyl group in carboxylic acid.
  • Smell – carboxylic acid (<>10 carbons) are wax-like solids.

5. Preparation of carboxylic acid

  • Oxidation of an alcohol
    The oxidation of ethanol is used to prepare ethanoic acid.
    C2H5OH + 2[O] –> CH3COOH + H2O
    Carried out by refluxing* ethanol with an oxidising agent
    [acidified potassium dichromate(VI) solution – orange colour turns to green /
    acidified potassium manganate(VII) solution – purple colour turns to colourless]
    * reflux = upright Liebig condense to prevent the loss of a volatile liquid by vaporisation.

6. Chemical properties of carboxylic acid

  • Acid properties
    Ethanoic acid is a weak monoprotic acid that ionises partially in water (produce a low concentration of hydrogen ions).
    CH3COOH <–> CH3COO- + H+
    Ethanoic acid turns moist blue litmus paper red.
  • Reaction with metals
    Ethanoic acid reacts with reactive metals (copper and metals below it in the reactivity series cannot react with ethanoic acid).
    (K, Na, Mg, Al, Zn, Fe, Sn, Pb, Cu, Hg, Au)
    2CH3COOH + Zn –> Zn(CH3COO)2 + H2
    In this reaction, a colourless solution (zinc ethanoate) is formed.
    2CH3COOH + Mg –> Mg(CH3COO)2 + H2
    In this reaction, a colourless solution (magnesium ethanoate) is formed.
  • Reaction with bases
    acid neutralises alkalis (sodium hydroxide).
    CH3COOH + NaOH –> CH3COONa + H2O
    In this reaction, a salt (sodium ethanoate) and water are formed.
  • Reaction with carbonates
    Ethanoic acid reacts with metal carbonates (calcium carbonate, magnesium carbonate, zinc carbonate).
    2CH3COOH + CaCO3 –> Ca(CH3COO)2 + CO2 + H2O
    In this reaction, a salt (calcium ethanoate), carbon dioxide and water are formed.
  • Reaction with alcohols (Esterification)
    Ethanoic acid reacts with alcohol (ethanol, propanol, butanol)
    CH3CO-OH + H-OC4H9 –> CH3COOC4H9 + H2O (Concentrated H2SO4 is a catalyst)
    In this reaction, an ester (colourless sweet-smelling liquid) (butyl ethanoate) and water are formed.

7. Uses of Carboxylic Acid

  • Carboxylic acid (methanoic acid and ethanoic acid) is used to coagulate latex.
  • Vinegar (dilute 4% of ethanoic acid) is used as preservative and flavouring.
  • Ethanoic acid is used to make polyvinvyl acetate which is used to make plastics and emulsion paints.
  • Benzoic acid is used as food preservative.
  • Butanoic acid is used to produce ester (artificial flavouring).

..........got it from http://berryberryeasy.com/........

carbon compound [part 5]

SPM Form 5 – Terminology and Concepts: Carbon Compounds (Part 5)

Non-Hydrocarbon – Alcohol

1. General formula: CnH2n-1OH

  • Where n = 1, 2, 3 … (n = number of carbon)

2. Alcohols are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms. 3. The functional group in alcohols is hydroxyl group, – OH.

Name of alcohol Molecular formula of alcohol
Methanol CH3OH
Ethanol C2H3OH
Propanol / Propan-1-ol C3H5OH
Butanol / Butan-1-ol C4H7OH
Pentanol / Pentan-1-ol C5H9OH
Hexanol / Hexan-1-ol C6H11OH
Heptanol / Heptan-1-ol C7H13OH
Octanol / Octan-1-ol C8H15OH
Nonanol / Nonan-1-ol C9H17OH
Decanol / Decan-1-ol C10H19OH

4. Physical properties of alcohol

Name Molecular formula Melting point (°C) Boiling point (°C) Physical state at 25°C
Methanol CH3OH -97 65 Liquid
Ethanol C2H3OH -117 78 Liquid
Propanol C3H5OH -127 97 Liquid
Butanol C4H7OH -90 118 Liquid
Pentanol C5H9OH -79 138 Liquid
  • Solubility in water – all members in alcohol are very soluble in water (miscible with water).
  • Volatility – all alcohols are highly volatile.
  • Colour and Smell – alcohols are colourless liquid and have sharp smell.
  • Boiling and melting points – all alcohols in general have low boiling points (78°C).

5. Chemical properties of alcohol

  • Combustion of alcohol Complete combustion of alcohol. C2H5OH + 3O2 –> 2CO2 + 3H2O (Alcohol burns with clean blue flames. Alcohol burns plenty of oxygen to produce carbon dioxide and water. This reaction releases a lot of heat. Therefore, it is a clean fuel as it does not pollute the air.) Other example: 2C3H7OH + 9O2 –> 6CO2 + 8H2O
  • Oxidation of ethanol In the laboratory, two common oxidising agents are used for the oxidation of ethanol which are acidified potassium dichromate(VI) solution (orange to green) and acidified potassium manganate(VII) solution (purple to colourless). C2H5OH + 2[O] –> CH3COOH + H2O Ethanol oxidised to ethanoic acid (a member of the homologous series of carboxylic acids – will be discussed in Part 6). Other example: C3H7OH + 2[O] –> C2H5COOH + H2O
  • Removal of water (Dehydration) Alcohol can change to alkene by removal of water molecules (dehydration). It results in the formation of a C=C double bond. CnH2n+1OH –> CnH2n + H2O C2H5OH –> C2H4 + H2O Two methods are being used to carry out a dehydration in the laboratory. a) Ethanol vapour is passed over a heated catalyst such as aluminium oxide, unglazed porcelain chips, pumice stone or porous pot. b) Ethanol is heated under reflux at 180°C with excess concentrated sulphuric acid, H2SO4. Other example: C3H7OH –> C3H6 + H2O

6. Uses of Alcohol

  • Alcohol as a solvent (cosmetics, toiletries, thinners, varnishes, perfumes).
  • Alcohol as a fuel (fuel for racing car, clean fuel, alternative fuel).
  • Alcohol as a source of chemicals (polymer, explosives, vinegar, fiber).
  • Alcohol as a source of medical product (antiseptics for skin disinfection, rubbing alcohol).

..........got it from http://berryberryeasy.com/........

carbon compound [part 4]

SPM Form 5 – Terminology and Concepts: Carbon Compounds

1. Comparing (Similarities and Differences) Properties of Alkanes and Alkenes

Physical Properties Alkanes Alkenes
Physical state Physical state changes from gas to liquid when going down the series. Same with alkanes.
Electrical conductivity. Do not conduct electricity at any state. Same with alkanes.
Boiling points and melting points Low boiling points and melting points (number of carbon atoms per molecule increases). Same with alkanes.
Density Low densities (number of carbon atom per molecule increases). Same with alkanes.
Solubility in water Insoluble in water (soluble in organic solvent) Same with alkanes.
Chemical Properties Alkanes

(Substitution reaction)

Alkenes

(Addition reaction)

Reactivity Unreactive Reactive
Combustion Burn in air and produce yellow sooty flame. Burn in air and produce yellow and sootier flame compare to alkanes.
Reaction with bromine solution No reaction. Decolourise brown bromine solution.
Reaction with acidified potassium manganate(VII) solution No reaction. Decolourise purple acidified potassium manganate(VII) solution.

2. Isomerism

Isomerism – phenomenon that two or more molecules are found to have the same molecular formula but different structural formulae.

Isomerism in alkanes

Molecular formula Number of isomers Structure name
CH4 - (no isomer) Methane
C2H6 - (no isomer) Ethane
C3H8 - (no isomer) Propane
C4H10 2 Butane2-methylpropane
C5H12 3 Pentane2-methylbutane2,2-dimethylpropane

Isomerism in alkenes

Molecular formula Number of isomers Structure name
C2H4 - (no isomer) Ethene
C3H6 - (no isomer) Propene
C4H8 3 But-1-eneBut-2-ene2-methylpropene
C5H10 5 Pent-1-enePent-2-ene2-methylbut-1-ene

3-methylbut-1-ene

2-methylbut-2-ene


carbon compound [part 3]

SPM Chemistry Form 5 – Terminology and Concepts: Carbon Compounds (Part 3)

Family of Hydrocarbon – Alkene

1. General formula: CnH2n
Where n = 2, 3, 4 … (n = number of carbon)

2. Alkenes are unsaturated hydrocarbons which contain one or more carbon-carbon (C = C) double bonds in molecules.

3. The functional group in alkenes is carbon-carbon double (C = C) bond.

Name of alkene Molecular formula of alkene
Ethene C2H4
Propene C3H6
Butene C4H8
Pentene C5H10
Hexene C6H12
Heptene C7H14
Octene C8H16
Nonene C9H18
Decene C10H20
  • Molecular formula is a chemical formula that shows the actual number of atoms of each type of elements present in a molecule of the compound.
    Example: molecular formula of butene is C4H2x4 = C4H8

4. Physical properties of alkenes

Name Molecularformula RMM Density(g cm-3) Physical state at 25°C
Ethene C2H4 28 0.0011 Gas
Propene C3H6 42 0.0018 Gas
Butene C4H8 56 0.0023 Gas
Pentene C5H10 70 0.6430 Liquid
Hexene C6H12 84 0.6750 Liquid
Heptene C7H14 98 0.6980 Liquid
Octene C8H16 112 0.7160 Liquid
Nonene C9H18 126 0.7310 Liquid
Decene C10H20 140 0.7430 Liquid
  • Solubility in water – all members in alkenes are insoluble in water but soluble in many organic solvent (benzene and ether).
  • Density of alkene – the density of water is higher than density of alkene.
    When going down the series, relative molecular mass of alkenes is higher due to the higher force of attraction between molecules and alkene molecules are packed closer together.
  • Electrical conductivity – all members in alkenes do not conduct electricity.
    Alkenes are covalent compounds and do not contain freely moving ions.
  • Boiling and melting points – all alkenes in general have low boiling points and melting points. Alkenes are held together by weak attractive forces between molecules (intermolecular forces) van der Waals’ force. When going down the series, more energy is required to overcome the attraction. Hence, the boiling and melting points increases.

5. Chemical properties of alkenes

  • Reactivity of alkenes
    Alkenes are more reactive (unsaturated hydrocarbon).
    Alkenes have carbon-carbon (C = C) double bonds which is more reactive than carbon-carbon (C-C) single bonds. All the reaction occur at the double bonds.
  • Combustion of alkenes
    Complete combustion of hydrocarbons (alkenes)
    CxHy + (x + y/4) O2 –> xCO2 + y/2 H2O
    C2H4 + 3O2 –> 2CO2 + 2H2O
    (Alkenes burn with sootier flames than alkanes. It is because the percentage of carbon in alkene molecules is higher than alkane molecules and alkenes burn plenty of oxygen to produce carbon dioxide and water)

    Incomplete combustion occurs when insufficient supply of oxygen
    C2H4 + O2 –> 2C + 2H2O
    C2H4 + 2O2 –> 2CO + 2H2O
    (The flame in the incomplete combustion of alkenes is more smoky than alkanes)

  • Polymerisation reaction of alkenes
    Polymers are substances that many monomers are bonded together in a repeating sequence.
    Polymerisation is small alkene molecules (monomers) are joined together to form a long chain (polymer).
    n
    CH2 = CH2 –> -(- CH2 – CH2 -)-n
    ethene (monomer)(unsaturated compound) –> polyethene polymer (saturated compound)
    It must be carry out in high temperature and pressure.
  • Addition of hydrogen (Hydrogenation)
    Addition reaction is atoms (or a group of atoms) are added to each carbon atom of a carbon-carbon multiple bond to a single bond.
    C2H4 + H2 –> C2H6 (catalyst: nickel and condition: 200°C)
    Example: margarine (produce from hydrogenation of vegetable oils).
  • Addition of halogen (Halogenation)
    Halogenation is the addition of halogens to alkenes (no catalyst of ultraviolet light is needed).
    Alkene + Halogen –> Dihaloalkane
    C2H4 + Br2 –> C2H4Br2
    In this reaction the brown colour of bromine decolourised (immediately) to produce a colourless organic liquid.
    Bromination is also used to identify an unsaturated (presence of a carbon-carbon double bond) organic compound in a chemical test.
  • Addition of hydrogen halides
    Hydrogen halides (HX) are hydrogen chlorine, hydrogen bromide, hydrogen iodide and etc. This reaction takes place rapidly in room temperature and without catalyst.
    CnH2n + HX –> CnH2n+1X
    C2H4 + HBr –> C2H5Br (Bromoethane)
    (There are two products for additional of hydrogen halide to propene. The products are 1-bromopropane and 2-bromopropane).
  • Addition of water (Hydration)
    Alkenes do not react with water under ordinary condition. It can react with a mixture of alkene and steam pass over a catalyst (Phosphoric acid, H3PO4). The product is an alcohol.
    CnH2n + H2O –> CnH2n+1OH
    C2H4 + H2O –> C2H5OH
  • Additional of acidified potassium manganate(VII), KMnO4
    CnH2n + [O] + H2O –> CnH2n(OH)2
    C2H4 + [O] + H2O –> C2H5(OH)2
    The purple colour of KMnO4 solution decolourised immediately to produce colourless organic liquid. Also used to identify the presence of a carbon-carbon double bond in a chemical test.

..........got it from http://berryberryeasy.com/........

carbon compound [part 2]

SPM Chemistry Form 5 – Terminology and Concepts: Carbon Compounds (Part 2)

A) IUPAC (International Union of Pure and Applied Chemistry) – is used to name organic compound.

Organic compound is divided into three portions which is Prefix + Root + Suffix.

  1. Prefix – name of the branch or side chain.
    General formula: CnH2n+1 –Where n = 1, 2, 3, … (n = number of carbon)
    Formula Branch or name of group
    CH3 - methyl
    C2H5 - ethyl
    C3H7 - propyl
    C4H9 - butyl
    C5H11 - pentyl

    Alkyl group signifies that it is not part of the main chain.

    Two or more types of branches are present, name them in alphabetical order.

    Number of side chain Prefix
    2 Di-
    3 Tri-
    4 Tetra-
    5 Penta-
    6 Hexa-

    More than one side chains are present, prefixes are used.

  2. Root – the parent hydrocarbon (denotes the longest carbon chain).
    Number of carbon atoms Root name
    1 meth-
    2 eth-
    3 prop-
    4 but-
    5 pent-
    6 hex-
    7 hept-
    8 oct-
    9 nan-
    10 dec-
    • The longest continuous (straight chain) carbon chain is selected.
    • Identify the number of carbon.
  3. Suffix – functional group.
    Homologous series Functional group Suffix
    Alkane - C – C - -ane
    Alkene - C = C - -ene
    Alcohol – OH -ol
    Carboxylic acid – COOH -oic
    Ester – COO – -oate

    Example: 4-methylhept-2-ene.

    Prefix + Root + Suffix

B) Family of Hydrocarbon – Alkane

1. General formula: CnH2n+2
Where n = 1, 2, 3, … (n = number of carbon)

2. Each carbon atom in alkanes is bonded to four other atoms by single covalent bonds.
Alkanes are saturated hydrocarbon.

Name of alkane Molecular formula of alkane
Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
Pentane C5H12
Hexane C6H14
Heptane C7H16
Octane C8H18
Nonane C9H20
Decane C10H22

Molecular formula is a chemical formula that shows the actual number of atoms of each type of elements
present in a molecule of the compound.

Example: molecular formula of butane is C4H2´4+2 = C4H10

Name Condensed structural formula of alkane
Methane CH4
Ethane CH3CH3
Propane CH3CH2CH3
Butane CH3CH2CH2CH3
Pentane CH3CH2CH2CH2CH3
Hexane CH3CH2CH2CH2CH2CH3
Heptane CH3CH2CH2CH2CH2CH2CH3
Octane CH3CH2CH2CH2CH2CH2CH2CH3
Nonane CH3CH2CH2CH2CH2CH2CH2CH2CH3
Decane CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

Structural formula is a chemical formula that shows the atoms of elements are bonded (arrangement of atoms) together in a molecule by what types of bond.

3. Physical properties of alkanes

Name Molecularformula RMM Density(g cm-3) Physical state at 25°C
Methane CH4 16 - Gas
Ethane C2H6 30 - Gas
Propane C3H8 44 - Gas
Butane C4H10 58 - Gas
Pentane C5H12 72 0.63 Liquid
Hexane C6H14 86 0.66 Liquid
Heptane C7H16 100 0.68 Liquid
Octane C8H18 114 0.70 Liquid
Nonane C9H20 128 0.72 Liquid
Decane C10H22 142 0.73 Liquid

Alkanes with more than 17 carbon atoms are solid.

  • Solubility in water – all members in alkanes are insoluble in water but soluble in many organic solvent (benzene and ether).
  • Density of alkane – the density of water is higher than density of alkane.
    When going down the series, relative molecular mass of alkanes is higher due to the higher force of attraction between molecules and alkane molecules are packed closer together.
  • Electrical conductivity – all members in alkanes do not conduct electricity.
    Alkanes are covalent compounds and do not contain freely moving ions.
  • Boiling and melting points – all alkanes in general have low boiling points and melting points.
    Alkanes are held together by weak intermolecular forces.

4. Chemical properties of alkanes

  • Reactivity of alkanes
    Alkanes are less reactive (saturated hydrocarbon).
    Alkanes have strong carbon-carbon (C – C) bonds and carbon-hydrogen (C – H) bonds.
    All are single bonds which require a lot of energy to break.
    Alkanes do not react with chemicals such as oxidizing agents, reducing agents, acids and alkalis.
  • Combustion of alkanes
    Complete combustion
    of hydrocarbons
    CxHy + (x + y/4) O2 –> xCO2 + y/2 H2O
    CH4 + 2O2 –> CO2 + 2H2OIncomplete combustion
    occurs when insufficient supply of oxygen
    CH4 + O2 –> C + H2O
    2CH4 + 3O2 –> 2CO + 4H2O
  • Substitution reaction of alkanes (Halogenation)
    Substitution reaction is one atom (or a group of atoms) in a molecule is replaced by another atom (or a group of atoms).
    Substitution reaction of alkanes take place in ultraviolet light.
    Example:
    Alkanes react with bromine vapour (or chlorine) in the presence of UV light.
    CH4 + Cl2 –> HCl + CH3Cl (Chloromethane)
    CH3Cl + Cl2 –> HCl + CH2Cl2 (Dichloromethane)
    CH2Cl2 + Cl2 –> HCl + CHCl3 (Trichloromethane)
    CHCl3 + Cl2 –> HCl + CCl4 (Tetrachloromethane)
    The rate of reaction between bromine and alkanes is slower than the rate of reaction between chlorine and alkanes.

..........got it from http://berryberryeasy.com/........

carbon compound [part 1]

SPM Chemistry Form 5 – Terminology and Concepts: Carbon Compounds

  1. Organic compoundscarbon containing compounds with covalent bonds.
  2. Inorganic compounds non-living things and usually do not contain carbon but few carbon containing inorganic compounds such as CO2, CaCO3 and KCN.
  3. Hydrocarbons – organic compounds that contain hydrogen and carbon atom only.
  4. Non-hydrocarbons – organic compounds that contain other elements (oxygen, nitrogen, iodine, phosphorus)
  5. Saturated hydrocarbons – only single bonded (Carbon-Carbon) hydrocarbons.
  6. Unsaturated hydrocarbons – at least one double / triple bonded (Carbon-Carbon) hydrocarbons.
  7. Complete combustion – organic compounds burn completely which form CO2 and H2O.
    Example: C2H5OH (l) + O2 (g) –> 2CO2 (g) + 3H2O (l)
  8. Incomplete combustion – organic compounds burn with limited supply of O2 which form C (soot), CO, CO2 and H2O.

Homologous Series

Homologous series – organic compounds with similar formulae and properties. It have the physical properties that change gradually as the number of carbon atoms in a molecule increases.

Carbon Compounds General Formula
Functional group
Alkane CnH2n+2 n = 1, 2, 3, … Carbon-carbon single bond
- C – C -
Alkene CnH2n n = 2, 3, 4, … Carbon-carbon double bond
- C = C -
Alkynes CnHn n = 2, 3, 4, … Carbon-carbon triple bond
- C = C -
Arenes CnH2n-6 n = 6, 7, 8, … - C = C -
delocalised / free to move around the ring
Alcohol CnH2n+1OH n = 1, 2, 3, … Hydroxyl group
- OH
Carboxylic Acids CnH2n+1COOH n = 0, 1, 2 Carboxyl group
- COOH
Esters CnH2n+1COOCmH2m+1 n = 0, 1, 2, …
m = 1, 2, 3, …
Carboxylate group
- COO -

Sources of Hydrocarbon:

1. Coal – from the lush vegetation that grew in warm shallow coastal swamps or dead plants slowly become rock. Mainly contains of hydrocarbon and some sulphur and nitrogen. It is used to produce: fertiliser, nylon, explosives and plastics.

2. Natural gas – from plants and animals and trapped between the layers of impervious rocks (on top of petroleum). Mainly contains of methane gas and other gas such as propane and butane. It is used for: cooking, vehicle and generate electrical power.

3. Petroleum – from plants and animals and trapped between the layers of impervious rocks. It is a complex mixture of alkanes, alkenes, aromatic hydrocarbons and sulphur compound. These compounds can be separated by using fractional distillation.

  • <>
  • 35°C – 75°C – Petrol (gasoline)
  • 75°C – 170°C – Naphtha
  • 170°C – 230°C – Kerosene
  • 230°C – 250°C – Diesel
  • 250°C – 300°C – Lubricating oil
  • 300°C – 350°C – Fuel oil
  • > 350°C – Bitumen

..........got it from http://berryberryeasy.com/........

mlm.....pagi2 yg terlalu hening~

ak xtw npe???

knpe nih....

aja tolong lah.....

just buku je...jgn la cmni....~

wake up!!!!!

jadual trial spm 2010 ~

jadual nih untuk bdk klas sains.....


23.9.2010 bm 1....bm 2
24.9.2010 bi 1....bi 2
27.9.2010 math 1....math 2
28.9.2010 sej 1....sej 2
30.9.2010 addmath 1....addmath 2
1.10.2010 bio 1....bio 2
4.10.2010 bio 3
5.10.2010 phy 1....phy 2
6.10.2010 chem 1....chem 2
7.10.2010 phy 3....chem 3
8.10.2010 bat 1....bat 2
12.10.2010 pqs
14.10.2010 psi 1....psi 2

September 7, 2010

korea....jepun....malaysia....?????


snsd...



suju...



wondergirl



hana yori dango..




hana kimi



hana kimi


dok kat malaysia.....
dgr lagu korea....
tgk cter jepun....

hussyyyhhh.....xtw nk kata ap dah!!!!

malaysia sonok....

lagu korea bez....

cter jepun menarik ckit...

hahaha...

bandingkan laaa....


September 6, 2010

penat tol...

segar'y......sedap seh tdo tym nih....hujan~~
huuuuuhuuuu~~~~
akk ak da lme lentok kt sblh nih....penat buat hntrn...
nk kawen la ktekn...
smlm ad knduri kt uma....tahlil ckit...mesy ckit...
psl knduri la kot...

td kms pggn mgkuk ngn abg muaz....
pastu kms peti ais....penat sehh....haha
act.....xdela penat sgt....

skang nih.....blurrrr...sgt

xtw....dgr lgu rye~~~

bju rye da bli....sdey.....bju rye kale ijau tp yg len kale biru...

nnt jd aneh...xnk!!

lnx la...salam~

September 5, 2010

Work, Energy, Power and Efficiency

Understanding Work, Energy, Power and Efficiency Physics form

Work
1. Work is defined as the product of the applied force and the displacement of an object in the direction of the applied force.
2. W = F x S
3. W= work done, F = force applied, S = displacement in the direction of force.
4. SI unit for work = Joule (J), other unit = Nm

5. Work is not done when:
a. The object is stationary a.k.a not moving
b. No force is appliedn the object in the direction of displacement.
c. The direction of motion of the object is perpendicular to that of the applied force.
6. When work is done to an object, energy is transferred to the object.

Energy (Energy is the capacity to do work)
1. Energy exists in different forms: kinetic energy, gravitational potential energy, elastic potential energy, sound energy, heat energy, light energy, electrical energy and chemical energy.
2. The unit for energy is Joule (J) – same as work
3. The work done is equal to the amount of energy transferred.
4. Kinetic energy is the energy of an object due to its motion.
5. Kinetic energy or work done is given by:
a. ½ Mv2

b. M = mass, v = velocity
c. Unit: Joule / kgm2s-2



6. Gravitational potential energy is the energy of an object due to its higher position in the gravitational field.
a. E = mgh
b. M = mass, g = acceleration due to gravity, h = height in metre

Conservation of energy
1. The principle of conservation of energy states that energy cannot be created or destroyed but can change from one form to another form of energy.
2. Total amount of energy remains the same.
eg:
3. When water falls from a dam, its potential energy changes to kinetic energy.
4. When a swing moves from one position to another position, its potential energy changes to kinetic energy alternately.

Power
1. Power is defined as the rate of doing work.

a. Power = (Work / Time)

b. P = power, W = work, T = time

2. SI unit for work is = watt (W).

Efficiency

1. Efficiency of a device is defined as the percentage of the energy input that is transformed into useful energy.

2. Efficiency = (useful Energy output / Energy input ) X 100%

a. Efficiency = (Useful power output / Power input) X 100%

b. Unit is given in percentage.




p/s : hope this note can help u....

kawan~





cute en ktorg.....


istilah kawan.....sahabat....teman..

sume'y sme tp isi'y laen....

sape yg ad kwn tw la kn....hahaha....

ak ad kwn.....rmi kwn....sgt ramai....
dr sekola rendah + tadika + sekola menengah......
klu nk dikira mmg terlalu ramai....ecceeehhh ayt cm poyos melampau je...

hahahahaa....

TYM KANAK2....
ak ad kwn plg baik....

ktorg 4 org slalu b'sme 4ever larhhh....
ecah+yanie+atin+ak la....

bez tol....nnt ak letak gmba diorg...

tp kitorg b'3 da...coz psl ap nta atin cm da xngam ngn kitorg ag...

lupe la....cter lme....sgt.....hyper lme la...

TYM DA AGK2 BESAR....

skang ak pon ad kwn baek gk....




kitorg b'3....

ak + shak + kin

shak + kin : the most bestest fren 4ever lahh.....(betapa bez'y ak describe korg)

hahahaha....ngn shak....ak pon xtw cmne persahabatan kitorg b'mula....

agk aneh....mmg aneh pon...hyper aneh lahhh....plek la...

tetibe tym form2 kitorg bole dok 1meja prep..b'2 je plak tuh....

padahal tym form1 ak xdela rpr sgt ngn dye....hahahaa

ngn kin lak....start form2 gak...coz ktorg satu dorm kot lgpon katil sebela je...

hahahaha....yg penting ktorg mkin rpt la skang....i really luv this!!!!!


ak ngn shak~


shak ngn kin~


kwn ak bkn diorg je tp rmi ag.....

sgt ramai......














ak ske ad rmi kwn2......shonok3x

pagi yg damai...

entah la....ak xcuak langsung....xde feel..cmne nih...trial tggl bpe ari je...
td tgh wat math pastu nta cmne bole t'pengaruh bukak tenet nih..

YA ALLAH......BANTULAH HAMBAMU INI......

ok...aja relaks jap....
lgu da abes.....dgr surah ashura jap....

bru tenang!!!!!
mission to accomplish!!!!!!

1st : prepare jadual blaja !!!!!!
2nd : jgn asyik tdo je
3rd : jgn nk lyn tenet je ooiiii
4th : ikut jadual la.....
aja yg hebat mesti bole wat kn !!!!

ohhh....ak pon blur-blur je nk smbung mne lps spm....???????

ak nk jd cam MINORU SHIROTA....
knl x?????

xknl la tuh...ishh ta pape tah...


ni gamba'y

xla hensem mne tp dye mmg hebat la....

dye yg jumpa bkteria baik tuh pastu buat air yakult....

bgus en dye nih.....bez'y klu ak pon cm dye!!!!

hwehehee.....nk berangan la....

k....chow~~

assalamualaikum...