SPM Chemistry Form 4 Notes – Terminology and Concepts: Chemical Formulae and Equations (Part 4)
April 28, 2010
Finally after a long wait, the final part (Part 4) of the long series, SPM Chemistry Form 4 notes on Chemical Formulae and Equations is here on Berry Berry Easy. In the first three parts, the relative atomic mass, relative formula mass, relative molecular mass, scales, properties, Standard Temperature Pressure (s.t.p.), empirical formula, molecular formula, covalent compounds, ions, ionic compounds and even prefixes were all discussed. All these are of utmost importance in understanding Chemistry. So all Form 4 students must understand them by now if you wish to understand other chapters. (For Form 5 students who have not mastered the aforementioned concepts, make sure you look back at previous posts and learn them before your SPM)
In this part, we’ll try to apply what you have learnt in the previous three parts with some examples. So get a pen and paper to follow through the steps. Good revision too if you have already understand it.
Form 4 – Terminology and Concepts: Chemical Formulae and Equations (Part 4)
Chemical Equation
1. Importance of chemical equation:
The types of reactants; the physical conditions; the quantity of reactants and products and stated in moles.
nA + nB –> pC + pD
2. Reactants are written in the left side of the reaction and products are written in the right side of the reaction.
- Example 1:
Word equation: Sodium hydroxide + sulphuric acid –> sodium sulphate + water
Chemical equation: NaOH + H2SO4 –> Na2SO4 + H2O
Balancing equation: 2NaOH + H2SO4 –> Na2SO4 + 2H2O
Complete chemical equation: 2NaOH + H2SO4 –> Na2SO4 + 2H2O - Example 2:
Word equation: Aluminium + copper(II) oxide –> aluminium(III) oxide + copper
Chemical equation: Al + CuO –> Al2O3 + Cu
Balancing equation: 2Al + 3CuO –> Al2O3 + 3Cu
Complete chemical equation: 2Al + 3CuO –> Al2O3 + 3Cu - Example 3:
Word equation: Nitrogen + hydrogen <–> ammonia
Chemical equation: N2 + H2 <–> NH3
Balancing equation: N2 + 3H2 <–> 2NH3
Complete chemical equation: N2 + 3H2 <–> 2NH3
3. Information obtainable from chemical equations.
- i) mass of reactants
- ii) volume of reacting gas
- iii) mass of products formed
- iv) volume of gas produced
- Example:
2 cm3 of lead (III) nitrate solution is added to excess of potassium iodide solution.
How many molecules of potassium nitrate will be formed?
[Relative atomic mass: N, 14; O, 16; K, 39; I, 127; Pb, 207; Avogadro's constant: 6.02 x 1023 mol-1]
Step 1: Write a complete chemical equation.
- Pb(NO3)2(aq) + 2KI(aq) –> PbI2(s) + 2KNO3(aq)
- From the equation, 1 mole of Pb(NO3)2 reacts with 2 moles of KI formed 1 mole PbI2 of and 2 moles of KNO3.
Step 2: Convert to moles.
- No. of moles of Pb(NO3)2
= Mass of Pb(NO3)2 / Relative molecular mass
= 2 / [207 + 2(14 + 3 x 16)]
= 6.04 x 10-3 mol
Step 3: Ratio of moles.
- Number of moles of KNO3/ Number of moles of Pb(NO3)2
= 2/1 - Number of moles of KNO3
= (2 x 6.04 x 10-3) / 1
= 12.08 x 10-3 mol
Step 4: Convert to the number of molecules of potassium nitrate.
- Number of molecules of KNO3
= 12.08 x 10-3 x 6.02 x 1023
= 7.27 x 1021
Once you have completed all parts in this series, you would have mastered the most basic of knowledge in SPM Chemistry. So make sure all Berry Readers understand the basics before moving on to more advance topics.
SPM Chemistry Form 5 Notes – Terminology and Concepts: Carbon Compounds (Part 6)
April 26, 2010
Berry Berry Easy would like to present you with the Part 6 of the SPM Form 5 Chemistry notes on Carbon Compound in the series. For those who missed out on the first 5 parts, the first 4 parts were on alkane and alkenes. Previously on part 5, was on the non-hydrocarbon alcohol. This part focuses on non-hydrocarbon carboxylic acids. SPM students typically ace through alcohols but have slight problems on carboxylic acids. So Form 5 SPM students would have to brace the difficulty of this subchapter.
SPM 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 carbon) are colourless and pungent 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).
Stay tune for the next part in the carbon compound series. So for SPM Form5 Chemistry students, do remember to check out Berry Berry Easy for more notes.
Berry Experiment – SPM Form 5 Chemistry – Glucose, Sugars/Starches as a Raw Material for Fermentation
April 24, 2010
Berry Berry Easy is pleased to start a new series on the experiments that students will be doing in the laboratory. All important experiments will be documented with pictures so students can understand the experiments better. So, to starts things off, we will be preparing ethanol by fermentation using various feedstocks such as glucose, sugars (fruit sugars – banana, pineapple, orange, grapes, apple and papaya) and starches (potatoes, tapioca and rice).
The happy and studious ”models” that you can see for this experiment depicted here are from the Form 5SNB of SMK Dato’ Jaafar, Johor Bahru where the Berry Berry Teacher is currently teaching.
Berry Experiment – SPM Form 5 Chemistry – Glucose, Sugars/Starches as a Raw Material for Fermentation
This experiment is “Laboratory Work 2.3 – Preparation of Ethanol by Fermentation” from the Integrated Curriculum for Secondary Schools Chemistry Form 5 Practical Book (pg 38).
(Photo captions can be found below the photos)
One week of fermentation process.
Berry Berry Grape Sucessful Fermentation!
Paper filtering process.
Gurjivan,Gregory, Gabriel, David and Hong Yaw obtained the ethanol by the fermentation of glucose (natural raw material - sugar)
Si Hao, Sarveen, Kavi and Zebedee's fermentation product turned the limewater chalky after a week.
Yim, Wilfred, Mohd Noel, Wee Han and Jun Kai examined the colour and smell of the fermentation product.
Ying Long, Ching Sheng, Yi Jing, Sui Sin and Alvin are preparing for the next step - Distillation - to separate water and ethanol.
Now that you have viewed the experiment photos, feel free to ask any questions related to it. (Don’t just ask for answers though, as the feedstock and method used will not be identical)
SPM Chemistry Form 5 Notes – Terminology and Concepts: Carbon Compounds (Part 5)
April 23, 2010
Berry Berry Easy would like to present you with the continuation of the SPM Form 5 Chemistry notes on Carbon Compound with Part 5 in the series. To recapitulate back issues, Parts 2-4 were focused on “alkanes”, “alkenes” and their differences. So today, you’ll learn about “alcohols”, its components within the homologous series, physical properties, chemical properties (and examples) and its uses. (Be sure also to check out the misuse of alcohols) So if you are well versed with the previous four parts, it is now time to hop into part 5 of the series to learn all about alcohols. (Rather easy topic if you have master the previous four parts)
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).
7. Misuse and Abuse
- Depressant drug
- Alcoholic drinks
- Addictive drug
BerryBerryEasy would like to advise all readers not to misuse alcohol in any manner. So for Young Berries who are already driving, do not drink and drive at the same time.
Berry Berry Easy has a new header designed by Berry Role Model #1 – Kendrick Ng
April 19, 2010
We hope we managed to catch the attention of our ‘long-time’ Berry Berry Easy readers with a change in the header for this website. Gone is the big strawberry with the wreath of leaves and in come a specially designed header by Kendrick Ng, our very first Berry Role Model. It’s rather a momentous event for a fledging site like ours to have a header designed by a rather prolific freelance artist. Thanks Kendrick!
Thanks Berry Berry Easy – New Header and Wallpapers from House88Kend
To view the full post which is located on Kendrick’s site, do click to view the post “Thanks Berry Berry Easy!”
[More to come]
SPM Chemistry Form 4 Notes – Terminology and Concepts: Chemical Formulae and Equations (Part 3)
April 14, 2010
Berry Berry Easy would like to present all Form 4 SPM student who took chemistry with the third part of the notes on Chemical Formulae and Equations. For those who have missed out on the previous two parts, do check them out and learn about relative atomic mass, relative formula mass, relative molecular mass and the various scales from different atom types, properties (with units) and the very important concept of Standard Temperature and Pressure (s.t.p). So let us begin on the most difficult topic in Form 4 so far, after the earlier easy topics.
SPM Form 4 – Terminology and Concepts: Chemical Formulae and Equations (Part 3)
Empirical and Molecular Formulae
1. Empirical (simplest ratio of atoms of each element that present in the compound) and molecular formulae (actual number of atoms of each element that are present in one molecule of the compound) indicate:
- the types of the elements
- the symbols of the elements and the ratio of atoms or
- moles of atoms of each element in a compound.
2. Molecular formula = (empirical formula)n
n is a positive number
| Compound | Molecular formula | n | Empirical formula |
| Carbon dioxide | CO2 | 1 | (CO2) = CO2 |
| Ethane | CH3 | 2 | (CH3)2 = C2H6 |
| Propene | CH2 | 3 | (CH2)3 = C3H6 |
| Glucose | CH2O | 6 | (CH2O)6 = C6H12O6 |
| Quinine | C10H12NO | 2 | C20H24N2O2 |
3. Chemical formulae for covalent compounds.
| Name | Chemical formula | Number of each element |
| Nitrogen gas | N2 | 2 nitrogen atoms |
| Oxygen gas | O2 | 2 oxygen atoms |
| Ammonia | NH3 | 1 nitrogen atom and 3 hydrogen atoms |
| Water | H2O | 2 hydrogen atoms and 1 oxygen atom |
4. Cations are positively-charged ions.
| Charge | Cations | Formula |
| +1 | Ammonium ion | NH4+ |
| +1 * | Copper(I) ion | Cu+ |
| +1 | Hydrogen ion | H+ |
| +1 | Lithium ion | Li+ |
| +1 * | Nickel(I) ion | Ni+ |
| +1 | Potassium ion | K+ |
| +1 | Silver ion | Ag+ |
| +1 | Sodium ion | Na+ |
| +2 | Barium ion | Ba2+ |
| +2 | Calcium ion | Ca2+ |
| +2 * | Copper(II) ion | Cu2+ |
| +2 * | Iron(II) ion | Fe2+ |
| +2 * | Lead(II) ion | Pb2+ |
| +2 | Magnesium ion | Mg2+ |
| +2 * | Manganese(II) ion | Mn2+ |
| +2 | Nickel(II) ion | Ni2+ |
| +2 * | Tin(II) ion | Sn2+ |
| +2 | Zinc ion | Zn2+ |
| +3 | Aluminium ion | Al3+ |
| +3 * | Chromium(III) ion | Cr3+ |
| +3 * | Iron(III) ion | Fe3+ |
| +4 * | Lead(IV) ion | Pb4+ |
| +4 * | Tin(IV) ion | Sn4+ |
* refer to the Roman numerals
5. Anions are negatively-charged ions.
| Charge | Anions | Formula |
| -1 | Bromide ion | Br- |
| -1 | Chloride ion | Cl- |
| -1 | Chlorate(V) ion | ClO3- |
| -1 | Ethanoate ion | CH3COO- |
| -1 | Fluoride ion | F- |
| -1 | Hydride ion | H- |
| -1 | Hydroxide ion | OH- |
| -1 | Iodide ion | I- |
| -1 | Manganate(VII) ion | MnO4- |
| -1 | Nitrate ion | NO3- |
| -1 | Nitrite ion | NO2- |
| -2 | Oxide ion | O2- |
| -2 | Carbonate ion | CO32- |
| -2 | Chromate(VI) ion | CrO42- |
| -2 | Dichromate(VI) ion | Cr2O72- |
| -2 | Sulphide ion | S2- |
| -2 | Sulphate ion | SO42- |
| -2 | Sulphite ion | SO32- |
| -2 | Thiosulphate ion | S2O32- |
| -3 | Nitride ion | N3- |
| -3 | Phosphate ion | PO43- |
| -3 | Phosphite ion | PO33- |
6. Chemical formulae for ionic compounds
| Name | Chemical formula | Number of cation | Number of anion |
| Zinc chloride | ZnCl2 | 1 Zn2+ | 2 Cl- |
| Copper(II) sulphate | CuSO4 | 2 Cu2+ | 2 SO42- |
| Aluminium sulphate | Al2(SO4)3 | 2 Al3+ | 3 SO42- |
7. Meaning of prefixes
| Prefix | Meaning |
| Mono- | 1 |
| Di- | 2 |
| Tri- | 3 |
| Tetra- | 4 |
| Penta- | 5 |
| Hexa- | 6 |
| Hepta- | 7 |
| Octa- | 8 |
| Nona- | 9 |
| Deca- | 10 |
8. Naming of chemical (non-metal) compounds with Greek numerical prefixes.
| Non-metal compound | Chemical formula |
| Carbon monoxide | CO |
| Carbon dioxide | CO2 |
| Sulphur dioxide | SO2 |
| Sulphur trioxide | SO3 |
| Carbon tetrachloride (tetrachloromethane) | CCl4 |
So, do come back for more Berry Essential Notes. If it is not simplified to its essense, then it is not from Berry Berry Easy. Let us do the summarising while you understand the core before you master the whole topic. Do share out this site with your friends.
Berry Berry Easy SPM/STPM Notes List – 11th April 2010
April 11, 2010
For the sake of our readers who might want to keep track on the notes so far on this new education based site, Berry Berry Easy has compiled the notes posted on Berry Berry Easy thus far. So be sure to copy/bookmark/save/print out the all the essential, short and berry berry easy notes
Berry Berry Easy – SPM and STPM notes compilation – 11th April 2010
Click on the links to open the notes.
SPM Form 4 Chemistry
- Berry Chemistry Form 4 Definition List – 28 October 2009
- SPM Chemistry Form 4 Notes – Introduction to Chemistry – 21 January 2010
- SPM Chemistry Form 4 Notes – The Structure of the Atom – 30 January 2010
- SPM Chemistry Form 4 Notes – Chemical Formulae and Equations (Part 1) – 25 February 2010
- SPM Chemistry Form 4 Notes – Chemical Formulae and Equations (Part 2) – 2 March 2010
SPM Form 5 Chemistry
- Berry Chemistry Form 5 Definition List – 28 October 2009
- SPM Chemistry Form 5 Notes – Rate of Reaction – 17 January 2010
- SPM Chemistry Form 5 Notes – Carbon Compounds (Part 1) – 19 March 2010
- SPM Chemistry Form 5 Notes – Carbon Compounds (Part 2) – 30 March 2010
- SPM Chemistry Form 5 Notes – Carbon Compounds (Part 3) – 2 April 2010
- SPM Chemistry Form 5 Notes – Carbon Compounds (Part 4) – 10 April 2010
STPM Form 6 Chemistry
- Berry Chemistry Form 6 Definition List Part 1 – 28 October 2009
- STPM Chemistry Form 6 Notes- Gases and Gas Law – 1 November 2009
- STPM Chemistry Form 6 Notes – Phases and Phase Change – 6 November 2009
- Berry Chemistry Form 6 Definition List Part 2 – 1 December 2009
- STPM Chemistry Form 6 Notes- Reaction Kinetics – 21 January 2010
- STPM Chemistry Form 6 Notes – Chemical Equilibrium (Part 1) – 25 March 2010
- SPM Chemistry Form 6 Notes – Chemical Equilibrium (Part 2) – 5 April 2010
SPM Form 4 Biology
- SPM Biology Form 4 Notes – Introduction to Biology – 6 February 2010
- SPM Biology Form 4 Notes – Cell Structure and Cell Organisation (Part I) – 9 February 2010
- SPM Biology Form 4 Notes – Cell Structure and Cell Organisation (Part II) – 12 February 2010
- SPM Biology Form 4 Notes – Cell Structure and Cell Organisation (Part III) – 4 March 2010
- SPM Biology Form 4 Notes – Cell Structure and Cell Organisation (Part IV) – 6 march 2010
The list of notes will grow to cater the needs of our Berry Readers. So do drop by frequently to get our new concise, easy and essential notes. We promise you that it’ll be Berry Berry Easy to understand. 
* Feel free to link this site to your blog/site for easy reference and to share them with your friends.
SPM Chemistry Form 5 Notes – Terminology and Concepts: Carbon Compounds (Part 4)
April 10, 2010
Welcome back to Berry Berry Easy. We are pleased to present you with the Part 4 of the SPM Form 5 Chemistry notes on Carbon Compound. For those who have learnt about “alkanes” in Part 2 and “alkenes” in Part 3, now you can compare between the two groups. You’ll be exposed to the similarities and differences in the properties of the two homologous groups and also isomerism in both groups. Be sure to check out the previous three parts if you have not done so.
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 |
As mentioned in the first part of the notes in this series, this will be a rather long set of notes. So, remember to drop by Berry Berry Easy to get updates for the notes.
