Useful websites
Chemguide
http://www.chemguide.co.uk/
If you are looking for quality revision notes
Doc Brown's Chemistry Clinic
http://www.wpbschoolhouse.btinternet.co.uk/page04/page04.htm
Notes and tests
Dr Rod Beavon's Chemistry Pages
http://www.rod.beavon.clara.net/chemistry_contents.htm
Notes and examination tips for the AS/A Level Chemistry.
Chemmy Bear
http://www.chemmybear.com/
Chemsoc Interactive Periodic Table
http://www.chemsoc.org/viselements/pages/pertable_fla.htm
Interactive Periodic Table of Elements
The Orbitron
http://www.shef.ac.uk/chemistry/orbitron/
3-D images of atomic orbitals and molecular orbitals.
The Organic Chemistry Review
http://www.organicchemistryreview.com/
Printable Notecards
S-cool! Revision Guide
http://www.s-cool.co.uk/topic_index.asp?subject_id=7&d=0
Extensive notes and sample questions.
RevisionNotes.co.uk
http://www.revision-notes.co.uk/A_Level/Chemistry/index.html
Revision notes
Beta-Theta.com Chemistry Section
http://www.beta-theta.com/Chemistry.html
Notes on topics relevant to AS/A Level Chemistry.
General Chemistry Online
http://antoine.frostburg.edu/chem/senese/101/index.shtml
Notes, articles, experiment simulations and tutorial for US students but relevant to A level students.
Thursday, March 25, 2010
Wednesday, February 3, 2010
Friday, January 15, 2010
Monday, January 11, 2010
Chemical bonding
Types of bonding
Ionic bond (between ions)
Ionic bond is the electrostatic force of attraction between the positive and negative ions as a result of transfer of electrons from an atom to another. (eg NaCl, MgCO3 )
Covalent bond (between atoms)
Covalent bond is the electrostatic force of attraction resulted by sharing of two electrons by two atoms.
Covalent bond can be found in simple molecular structure ( discrete molecules eg O2, CO2 ) and giant covalent structure (with a network of covalent bonds eg C(graphite), C(diamond), SiO2,,Si ]
Metallic bond ( between positive ions surrounded by sea of delocalised electrons)
Metallic bond is the electrostatic attractions between the cations and the delocalised electrons surrounding the cations. (eg Mg, Al , Na, Ag, Pb, Sn)
3 types of intermolecular forces ( weak forces between molecules)
London or dispersion forces occurs are weak forces occur between non- polar molecules , eg: CH4, Cl2, CO2
Dipole-dipole forces are forces occur between polar molecules, eg HCl , H2S, SO2
Hydrogen bonding is the electrostatic attraction forces between H atom bonded to a very electronegative atom and the lone pair of electrons from a very electronegative atom such as. F,O or N atom (eg HF, NH3, H2O ,amines and alcohols) Hydrogen bonding causes higher boiling points of hydrides, solubility of carboxylic acids, alcohols and amines, dimerisation of carboxylic acids and low density of ice.
Ionic bond (between ions)
Ionic bond is the electrostatic force of attraction between the positive and negative ions as a result of transfer of electrons from an atom to another. (eg NaCl, MgCO3 )
Covalent bond (between atoms)
Covalent bond is the electrostatic force of attraction resulted by sharing of two electrons by two atoms.
Covalent bond can be found in simple molecular structure ( discrete molecules eg O2, CO2 ) and giant covalent structure (with a network of covalent bonds eg C(graphite), C(diamond), SiO2,,Si ]
Metallic bond ( between positive ions surrounded by sea of delocalised electrons)
Metallic bond is the electrostatic attractions between the cations and the delocalised electrons surrounding the cations. (eg Mg, Al , Na, Ag, Pb, Sn)
3 types of intermolecular forces ( weak forces between molecules)
London or dispersion forces occurs are weak forces occur between non- polar molecules , eg: CH4, Cl2, CO2
Dipole-dipole forces are forces occur between polar molecules, eg HCl , H2S, SO2
Hydrogen bonding is the electrostatic attraction forces between H atom bonded to a very electronegative atom and the lone pair of electrons from a very electronegative atom such as. F,O or N atom (eg HF, NH3, H2O ,amines and alcohols) Hydrogen bonding causes higher boiling points of hydrides, solubility of carboxylic acids, alcohols and amines, dimerisation of carboxylic acids and low density of ice.
Thursday, December 31, 2009
Friday, December 4, 2009
Tar college Open day
If you want an affordable and quality education, come and find out more at Tar College Open Day.
Wednesday, November 4, 2009
Yew Shy Gin
On 2nd November 2009, three Utar students drowned after they were swept away by strong current during an outing to Batu Berangkai Waterfall, Kampar. (my hometown). One of them is Yew Shy Gin.
I used to go to this waterfall when I was a student. Well, this place is quite dangerous especially after it rains as there will be a water gush from the top.
By the way, Shy Gin did her A-level in Tar College.
She was my former student from the class of SN7c.
Rest In Peace
My condolences to her family.
I used to go to this waterfall when I was a student. Well, this place is quite dangerous especially after it rains as there will be a water gush from the top.
By the way, Shy Gin did her A-level in Tar College.
She was my former student from the class of SN7c.
Rest In Peace
My condolences to her family.
Friday, October 23, 2009
Trial Exam Sept 2009 Paper 1 and 2
Sorry, for the long silence. Take me some time to look for the soft copy.
Paper 1
Ans for Paper 1
Paper 2
Ans for Paper 2
Paper 1
Ans for Paper 1
Paper 2
Ans for Paper 2
Saturday, September 12, 2009
Saturday, August 8, 2009
A2 Quick Revision Notes
Quick revision downloaded from lanther.co.uk
http://www.4shared.com/file/123745687/3d38ace0/A2_notes.html
http://www.4shared.com/file/123745687/3d38ace0/A2_notes.html
Thursday, July 16, 2009
Video on Nanotechnology
For those who want to watch again the video on nanotechnology which I had shown in my previous class , please click the link below:
http://www.youtube.com/watch?v=JqMh5NYsRck
http://www.youtube.com/watch?v=8Kg_Lyg_qcM&feature=related
http://www.youtube.com/watch?v=JqMh5NYsRck
http://www.youtube.com/watch?v=8Kg_Lyg_qcM&feature=related
Saturday, July 4, 2009
Symbols in marking scheme and guide to writing a good answer
Symbols used in marking scheme:
/ - means that the responses are alternatives and either answer should receive full credit.
( ) - means that a phrase/word is not essential for the award of the mark, but helps the
examiner to get the sense of the expected answer.
Phrases/words in bold - means that the phrase or the actual word is essential to the answer.
Ecf (error carried forward)- means that a wrong answer given in an earlier part of a question is
used correctly in answer to a later part of the same question.
Guide to writing a good answer
1) Make the meaning of your answer clear to the examiner.
2) Make sure that the answer makes sense.
3) Answers must be in the correct context. In other words, your answers must answer the
questions.
4) Write legibly – the examiner must be able to read your handwriting and the font of your
handwriting should be big enough for them to read easily. Don’t forget, most examiners are
40s or 50s something and many of them are short-sighted.
5) Your words or sentences should have the accurate use of spelling, grammar and punctuation
in order to make the meaning clear.
6) Organise information clearly and coherently.
7) Use specialist vocabulary when appropriate.
/ - means that the responses are alternatives and either answer should receive full credit.
( ) - means that a phrase/word is not essential for the award of the mark, but helps the
examiner to get the sense of the expected answer.
Phrases/words in bold - means that the phrase or the actual word is essential to the answer.
Ecf (error carried forward)- means that a wrong answer given in an earlier part of a question is
used correctly in answer to a later part of the same question.
Guide to writing a good answer
1) Make the meaning of your answer clear to the examiner.
2) Make sure that the answer makes sense.
3) Answers must be in the correct context. In other words, your answers must answer the
questions.
4) Write legibly – the examiner must be able to read your handwriting and the font of your
handwriting should be big enough for them to read easily. Don’t forget, most examiners are
40s or 50s something and many of them are short-sighted.
5) Your words or sentences should have the accurate use of spelling, grammar and punctuation
in order to make the meaning clear.
6) Organise information clearly and coherently.
7) Use specialist vocabulary when appropriate.
Tuesday, June 30, 2009
Change of ph to f
CIE has changed the following terms:
New term for sulphate is sulfate
thiosulphate is thiosulfate
sulphite is sulfite
sulphur is sulfur
disulphide to disulfide
New term for sulphate is sulfate
thiosulphate is thiosulfate
sulphite is sulfite
sulphur is sulfur
disulphide to disulfide
Saturday, June 27, 2009
Xtreme link
Change of Xtremepaper link
http://www.planet-master.com/
Many thanks to you, Leong Seek for your information
http://www.planet-master.com/
Many thanks to you, Leong Seek for your information
Wednesday, June 3, 2009
Important Notice
To all students taking AS and A2 Examinations:
You are reminded again that you are not allowed to discuss anything about the question papers in the forum or blog within 24 hours after your paper. Don't forget some of the candidates in other parts of the world have not sat for the papers due to the different time zones. Failure to observe this rule means you are in trouble. Good luck
You are reminded again that you are not allowed to discuss anything about the question papers in the forum or blog within 24 hours after your paper. Don't forget some of the candidates in other parts of the world have not sat for the papers due to the different time zones. Failure to observe this rule means you are in trouble. Good luck
Sunday, May 31, 2009
Saturday, May 16, 2009
Think before you use
Waste decomposition Rate
Styrofoam is not composed
Plastic bottle takes at least 1 million years
Disposable diaper 500 to 600 years
Aluminium tin 200 to 500 years
Leather shoes 40 to 50 years
Newspaper 1 month
Styrofoam is not composed
Plastic bottle takes at least 1 million years
Disposable diaper 500 to 600 years
Aluminium tin 200 to 500 years
Leather shoes 40 to 50 years
Newspaper 1 month
Source : Star
Tuesday, May 5, 2009
Never judge a book by the cover
I was truly astounded by the talent of Susan Boyle when I watched her singing on the Britain's Got Talent (from Youtube). Her performance received a standing ovation from the live audience and later took the world by storm. The numbers who watched her videos on her audition have climbed to almost 200 millions and the figure is still growing.
What's so special about her? She is a 47 years old lady whose appearance is #@?/... but possess a golden voice. Watch her sing and you would understand what I meant.
http://www.youtube.com/watch?v=9lp0IWv8QZY
What's so special about her? She is a 47 years old lady whose appearance is #@?/... but possess a golden voice. Watch her sing and you would understand what I meant.
http://www.youtube.com/watch?v=9lp0IWv8QZY
Sunday, April 26, 2009
Wednesday, April 15, 2009
AS Practical Guide II
Guide to Potassium manganate(VII) titration
· For KMnO4 titration, no indicator is added because KMnO4 acts as its own indicator and it would change to pale pink colour at the end point.
· KMnO4 titration is used to determine the concentration of Fe2+ (Iron(II) ions) , H2O2 (hydrogen peroxide) and C2O42- (ethanedioate).
· KMnO4 titrations must be carried out in acidified condition because in neutral or alkaline solution, brown solid MnO2 is formed and as a result it would be difficult to detect the end point.
· To acidify, sulphuric acid is used and not other acids such as hydrochloric acid and nitric acid because the chloride ions or nitrate ions would also be oxidised.
· Most KMnO4 titrations should be carried out at room temperature except titration involving C2O42- which is normally carried out at 70 oC. For ethanediote, any temperature lower than 70 oC could cause the precipitation of MnO2.
· Titration using KMnO4 solution should be carried out slowly. A brown precipitate of MnO2 is formed when KMnO4 is dropped from the burette too quickly.
.
Guide to Iodine-thiosulphate titration
· Starch is used as an indicator in this titration
· The starch solution should not be added at the beginning of the titration. The reason is at this stage, there is a high concentration of iodine and iodine would be adsorbed onto the starch molecule.
· The starch solution should be added towards the end of the titration when the reaction mixture turns pale yellow. (Warning: not too pale as you may overshot the endpoint)
· The starch solution will produce a dark blue colour with iodine.
· At the end point ,the solution turns colourless.
· Be careful, the solution may become blue again due to the atmospheric oxidation of iodide (from potassium iodide). You shouldn’t continue titrating again.
· For KMnO4 titration, no indicator is added because KMnO4 acts as its own indicator and it would change to pale pink colour at the end point.
· KMnO4 titration is used to determine the concentration of Fe2+ (Iron(II) ions) , H2O2 (hydrogen peroxide) and C2O42- (ethanedioate).
· KMnO4 titrations must be carried out in acidified condition because in neutral or alkaline solution, brown solid MnO2 is formed and as a result it would be difficult to detect the end point.
· To acidify, sulphuric acid is used and not other acids such as hydrochloric acid and nitric acid because the chloride ions or nitrate ions would also be oxidised.
· Most KMnO4 titrations should be carried out at room temperature except titration involving C2O42- which is normally carried out at 70 oC. For ethanediote, any temperature lower than 70 oC could cause the precipitation of MnO2.
· Titration using KMnO4 solution should be carried out slowly. A brown precipitate of MnO2 is formed when KMnO4 is dropped from the burette too quickly.
.
Guide to Iodine-thiosulphate titration
· Starch is used as an indicator in this titration
· The starch solution should not be added at the beginning of the titration. The reason is at this stage, there is a high concentration of iodine and iodine would be adsorbed onto the starch molecule.
· The starch solution should be added towards the end of the titration when the reaction mixture turns pale yellow. (Warning: not too pale as you may overshot the endpoint)
· The starch solution will produce a dark blue colour with iodine.
· At the end point ,the solution turns colourless.
· Be careful, the solution may become blue again due to the atmospheric oxidation of iodide (from potassium iodide). You shouldn’t continue titrating again.
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