**This article is written by JC A level H2 / H1 Chemistry tutor - Mr Chong**
[This page was last updated on 8 Jan 2020]
Hi JC H1/H2 students and international visitors,
Welcome to my blog.
- 2018 Cambridge exam papers comments
- Biochemistry questions
- Arrow pushing mechanism in organic chemistry
- Organic chemistry
- Group 17 (Group VII) chemistry
- Some topics to take note of
- Information for those aiming for a distinction in H2 chemistry in the year 2019
- Chemical Bonding
- Exam revision
- How to tackle organic chemistry
- Optional Topics to Explore
This blog may help JC (Junior College) students in Singapore to cope with the Cambridge-Singapore GCE A level (H2) assessment. Organic Chem occupies a distinctive and important position in the Singapore Chem syllabus.
Thank you for your continued support of my blog. I am honored to serve you. You are free to look around and find information that you may use in your course of study.
Do keep an open mind and be positive about learning the analytical skills in chem that will be for use throughout your adult life. Chemistry is one of the central subjects in modern life and it interfaces well with many disciplines.
If you have tuition with me, I will try to help you to secure the basics. The below topics are actually quite optional and I shall do with you only when you are ready or we may not do them at all. I usually assign minimal homework for students. I am patient and I do not give much stress to the students. So do not worry about that!!!! :)
For any topics mentioned in the post, you may wikipedia on the topics or read up a general university chem textbook / university organic chemistry textbook / JC textbook in your school library. You may just read a few topics that I mentioned. For those who are really serious about chemistry, you may wish to purchase one or two chemistry textbooks so that you can refer to the textbooks at home in case your school notes are inadequate in certain sections.
For the new syllabus of H2 chemistry, the practical paper is of problem to many students. In last year's prelims, many students could not finish the practical papers of various JCs and Cambridge exam papers as they were tedious. Students need to spend time brushing up on practical concepts and have fast reflexes in doing titration, energetics etc experiments.
Energetics / kinetics experiment or planning questions may appear in 2020 prelims or Cambridge exams.
H2 Chemistry students may borrow H1 chemistry notes on nanochemistry and polymers and quickly scan through the topics. Polymerisation is not in the syllabus of H2 Chemistry, but it has appeared in Cambridge H2 Chemistry exam papers before
For 2017 papers 2 and 3 of Cambridge exams, some questions seemed open-ended and ambiguous and different from tutorial and prelim questions. Students needed to be resourceful and creative to suggest answers that were not standard type questions.
For JC1/2 students, Lewis Acids and Bases are quite likely to appear in tests this year.
The new formulae introduced in physical chemistry are very likely to appear this year. Ask your teacher which are the new formulae.
Nernst equation in electrochemistry may appear for JC2 prelim papers.
α,β-unsaturated ketone appeared in one 2018 Cambridge exam question, so that means Aldol condensation and related organic chemistry reactions may appear this year. Carbonyl compounds chemistry is one of the toughest topics in university chemistry, and Cambridge has finally used this unsaturated ketone in 2018 question. So hardworking students may look through an university organic chemistry textbook such as by David Klein and learn some reactions of carbonyl compounds at university level. There are a lot of carbonyl compound reactions at university level.
Also, even in 2018 O level chemistry papers, there was a simplified ion chromatography question which was learned in university year 2. Perhaps, the Cambridge and MOE examiners are all out to set tougher and atypical papers.
As lectures are progressing at a fast speed, before each lecture, students can skim through the sections of the lecture notes to get an idea of what the lecture will be about. Always get the big picture and main concepts in each lecture.
The examiners did not use their full strengths in setting papers in the last few years. So just take note that the examiners have lots of experience and they know the weak spots of students and teachers of MI, HCI and RI teachers. They know how JC teachers teach their students and the strengths and weaknesses of each JC and their teachers. They know all the strengths and weaknesses of the students of each JC. So just get prepared to face a tough paper and not lapse into complacency.
One of the papers would be atypical this year. It could be Paper 2 or Practical Paper. So do not underestimate the practical paper, which requires lots of preparation. Lots of young teachers are not prepared adequately for the new practical paper, so you may need some help, perhaps by taking up tuition or getting the practical notes of various JCs.
One solvent appeared in Cambridge papers and in some prelim papers, so students may read up on solvents such as furan, dimethylformamide.
There is a H2 Chemistry summary book titled "A level H2 Chemistry Key Concepts" written by Adeline Chew, published by EPH.
Students may like to look up on wikipedia on phosgene and its ability to form polymers with another monomer.
You may wish to read up on:
You may also like to explore optical and geometric isomerism in transition metal chem in the Zumdahl textbook, which is in university chemistry syllabus but may appear in prelim papers.
Let us be consistent in our daily reading of lectures, and do our tutorials faithfully (I know that the sense of weariness of doing tutorials has set in; it is the time for half done tutorials in JC2; been there, done that before. But keep pressing on!!! You can do it and achieve it for your dream course in university or some other routes!!! Sometimes setbacks can be a catalyst for even greater success, as a start-up entrepreneur shared in her latest book!!)
There have been many additions to the contents of International Cambridge Chem exam syllabus in 2020.
Many JC teachers have taken materials from university organic chem textbooks and set new reactions in the prelim papers beyond the scope of H2 and H3 syllabuses. So, just be prepared for that!!
Please pay close attention to organic chemistry topics, as this section is highly important. When you are ready for the challenge, you may want to reproduce summarized reaction charts (with reagents and reaction conditions) by functional groups of all reactions in organic chemistry. Hence, it makes sense to go to the library and get a book on speed memory techniques since lots of memory work (and more importantly, understanding) is needed for chemistry.
Arrow pushing mechanism in organic chemistry
You may like to ask your tutor to teach you arrow pushing mechanisms in organic chem. This is only fully taught in year 1/2 NUS/NTU, and has been brought down to A levels in exams since 2010.
There is an organic chem textbook that was published in 2012 that is written by 3 authors, one of whom is a Cambridge University author. Since Cambridge University examiners set the exams, you may get some clues from this textbook.
Title : Organic Chemistry (2nd edition)
Authors : Jonathan Clayden, Nick Greeves, Stuart Warren
Publisher : Oxford University Press
You may wish to briefly skim through the earlier chapters and come trained to tackle higher order thinking questions in the examinations. If you keep cool in exams and extend your knowledge of chemistry concepts, you should be able to tackle novel problems in the exams. This text is not composed in a easy to read manner and is more targeted at university senior undergraduates.
A simplified explanation of how chem works is : like charges repel each other, unlike charges in ions attract each other. From this concept, the whole of chem builds up into a "superstructure of cohesive knowledge".
But you have to secure your basics first. These matters that I mention are the choices that give you an edge in chemistry.
The examiners are gonna set some NUS/NTU year 1/2 questions in this year's Cambridge papers. So there will be new reactions and functional groups not encountered in A levels that you have never seen before in organic chemistry, but they will be an extension of what you have learned before. So keep cool and get your fundamentals right.
<<For more secrets to scoring in A level Chemistry, try tuition with Mr Chong, the blog owner! Whatsapp Mr Chong, the tutor, at 82875873. >>
Organic Chemistry questions are highly likely to take up more than 40% of your prelim exam papers. So prepare adequately for them. Physical chem questions may occupy about 25-30%. This is just a rough guide as it varies from JC to JC (Junior College).
You may want to ask your teacher nicely to give your class many organic chemistry elucidation questions in Mar - Apr 2020. The examiners favor structural elucidation problems in organic chemistry. You can find some problems in prelim packages.
There are also functional groups taught at university level, just for an example: thiols, -SH, that have appeared in exam papers. Examiners can set the exam paper in a contextual situation.
By the way, medicinal (drug) chemistry and biochemistry may be the hottest trends among researchers right now. A biochemistry question appeared in 2016 exam papers.
So you may want to study Chemical kinetics - enzymes. Sometimes, intuition can prove to be better than logic. A question really came out in 2014 exam papers.
Those who have a little time to spare and are game for the challenges, you may desire to practise John McMurry's or Janice Smith's Organic Chemistry textbook questions, especially those of the latter chapters, eg. hydroxy compounds, ***** carbonyl compounds. (Real complex and important topic!!) *****
You are always up to the challenge!!! Our brain structures are complex enough to adapt and generate new neural connections.You may want to ask your teacher to teach you about resonance. It is out of the syllabus, but this term appeared in MCQ 2012 Cambridge exam papers.
Also, if your teacher did not teach Williamson ether synthesis in halogeno derivatives, please learn it.
** A level chemistry tuition is available. Pls contact (sms/ whatsapp) Mr Chong at 82875873 or e-mail me at email@example.com. More 'secrets' to reveal in my coaching sessions.
Some topics to take note of
You may like to revise chemical bonding (a tricky topic), energetics (an important topic) and organic chemistry if your school has started on organic chem. As there is great continuity in the topics in organic chemistry, the minimum you can do in your free time is to revise your organic chemistry, as 2020 will be booming at higher speeds.
For those schools that did ionic equilibrium, it is a very difficult topic for students. So revise it and practise a few questions here and there.
You can also do mind maps for some of the topics you are unsure of. Using analogies, similarities, comparison and contrasts can be another method to ensure your learning.
Ask your school mates for ideas. Collaboration is the key in the 21st century world.
Information for those aiming for a good grade in H2 chemistry in the year 2020:
Do you know how to draw the Lewis structure of HgC2N2O2? Wiki for mercury fulminate to check the answers.
Maybe you like to do the Cambridge exam papers from 2007-2020.
Maybe the strategy now could be to brush up on the theory aspect of weaker topics and to practise lots of Singapore-Cambridge exam papers, and prelim papers.
Group 17 (Group VII) elements
You may like to study the effects of dilute aqueous ammonia and concentrated ammonia on chloride, bromide and iodide ions. This is found in the chapter of Group 17 and also ionic equilibria.
Will Cambridge like H-O-N=O? Or HClO3? Or CNBr? Or H2C=N-H? Or Br-CN? Or NOCl?
Not sure whether global warming may come out in exams? Do you know what is the greenhouse gas (GHG) nitrous oxide (laughing gas) N2O has chemical structure ? Try working out the dot and cross diagram. Also, can you name three greenhouse gases?
Are there anything special about the bond lengths of the C-C and C=C bonds in buta-1,3-diene? Wiki- about this molecule. (Topic: conjugation in diene compounds)
Heating magnesium carbide in nitrogen produces magnesium cyanamide:
MgC2 + N2 --> MgNCN + C
Draw the dot and cross diagram of C2(2-) ion and cyanamide (NCN(2-) ion. "
How about types of hybridization of non-hydrogen atoms in CH3CN and HN=NH molecules?
Carbon suboxide, or tricarbon dioxide, is an oxide of carbon with chemical formula C3O2 or O=C=C=C=O. (Courtesy of www.wikipedia.org) Will Cambridge like such molecules? It has come out before in the papers. It is your guess and my guess.
You may want to google for Ni(CO)4 (nickel carbonyl complexes).
A trick about organic chemistry
For organic chemistry mechanisms, you need to learn them well and reproduce them almost perfectly in the exams. Organic chemistry is understanding first, then memory work is next. In a chemical reaction, first understand which functional groups are changed as you go from reactants to products, and identify the electronegativity (please revise this in both chemical bonding and organic chemistry), nucleophile, electrophile or free radical, and check whether it is a substitution, addition, elimination or others reaction. Lastly, it is to remember the reaction conditions and catalysts. There are usually reasons why certain catalysts are used in certain reactions.
How to tackle organic chemistry
For some chapters, you need to know the details of the mechanisms very well. It requires some knowledge of nucleophiles, electrophiles or free radicals and the electron flow (eg. nucleophilic attacks). Next is to know whether the reaction is an addition, substitution or elimination or even redox reaction. (or other types of reactions)
After understanding the reactions, next is to commit into memory (with some understanding)
the reaction conditions and to practise as many questions as possible. You need to know the functions of reagents used in organic chemistry.
**** Drawing inspiration from Rod Beavon's chemistry site, you may want to look at esters, fats and oils. Fats or triglycerides appeared in 2016 exam papers.
For 3 challenging exam style questions (mainly on organic chemistry, pls see : http://alevelchemistrysg..com/2012/03/fun-questions-inspired-by-research.html )
OPTIONAL TOPICS TO EXPLORE
Good Knowledge to learn if you are aiming for a distinction in chemistry:
Stay cool! (: It is a long list, but you may just want to study some topics. Chemistry fanatics may spend much more time on the advanced A level topics!
Cambridge may set questions based on compounds found in soil and rocks.
Ease of overlap of 2p vs 3p orbitals to form pi bonds
(eg. N2 vs P4, CO2 vs SiO2)
Effect of percentage s (or p) character on C-C sigma
pKa of amino acids and how they protonate/deprotonate in acidic/alkaline medium
Unit cells - found in chemical bonding of textbooks. It is out of syllabus but came out in 2011.
Fuel cell – practise prelim papers for novel fuel cells (including hydrogen fuel cells) (Electrochem chapter)
Bond length, delocalisation of electrons in resonance structures , hybridisation
Formal charges in drawing Lewis structures - chemical bonding (came out in 2011 exam papers)
Isotopes of hydrogen
Solubility of Group 2 hydrogencarbonates, carbonates, hydroxides and sulfates. (Inorganic chemistry)
Transition metal – absorption spectrum, colours of transition metal ions and their compounds, eg. Colour of [CuCl4]2- complex. (Cambridge loves this!) Reaction of copper(II) ions with dilute and concentrated hydrochloric acid. Colours and chemistry of manganese, iron, vanadium and chromium compounds. Colours of complexes came out in 2011 and 2013 exam papers.
Simple Crystal Field theory (strong vs weak field ligands,
high spin vs low spin complexes)
Fullerenes, carbon nanotubes (found in general chemistry textbook), graphene
* Clock reactions in chemical kinetics
Ellingham diagrams in Gibbs Free energy and Entropy
***Diagonal relationships (eg. between Beryllium and Aluminium)
[New] 1,2-hydride shift or alkyl shift (carbocation rearrangement)
[New] Protecting groups in alcohols
***** Practical organic chemistry – eg. How Reflux process is actually done, separating organic products from their impurities, apparatus for performing organic experiments, how aspirin is manufactured, using different solvents to separate the various products
Grignard Reagent – Organic chemistry. Read up in an organic chemistry textbook
Polymerisation – Organic chemistry. It is out of syllabus but appeared in 2010 and 2015 exam papers
Reaction of alkyl halides with sodium ethoxide (also E1 / E2 versus SN1 / SN2 reactions); Williamson Ether synthesis
addition-elimination mechanism for nucleophilic acyl substitutions
Nucleophilic Acyl Substitution (addition-elimination mechanisms involving : esters, amides, acyl halides)
Ethers & Epoxides (mechanisms) I think epoxides came out in 2014 exam papers.
Organic Chemistry Redox reactions (mechanisms for reduction, oxidation states within organic compounds)
Azo-dye formation and diazonium salt formation (mechanism)
******* Arrow pushing in organic chemistry mechanisms
Dienes (resonance and bond lengths)
Hofmann degradation of amides (Came out in 2011 Exam Papers)
Friedal-Craft alkylation and acylation of benzene (including mechanisms)
Diels-Alder reaction (found in university organic chemistry textbook from your school library)
The differences between reducing agents such as LiAlH4, NaBH4 and hydrogen gas with nickel / palladium / platinum catalysts
How does LiAlH4 react with water?
Conformation of cyclohexane (found in organic chemistry textbook)
Alkyne chemistry (came out in 2014 exam papers) and sp hybridisation
(Cp)2Fe where Cp is cyclopentadiene
[New] Simple organometallic chemistry (eg. 18 electron rule). Some JC teachers may set prelim questions based on university Chemistry topics.
Hofmann rearrangement (mechanism)
Aldol and Claisen condensation reactions (mechanism)
Electrophoresis of Amino acids (migration to cathode vs
anode) based on their Isoelectric points
Free radical organic polymerisation reactions and their mechanisms
Some general advice
Work life in the Shenton Way area may be more challenging than school life ; so cherish your study life. Global situations are really unpredictable in the 21st century. With you going to the workforce in the next 4-7 years, will Singapore still be competitive in 2025?
Listen to your passions and heart. What is your path after A levels? Success in life is about finding your sweet spot and developing in your passion area. A doctor or a teacher or an artist can be very happy serving in a rural area and earning little money.
Be adequately prepared. My advice is to have sufficient sleep the day before chemistry exams and be prepared for surprises during the exam. Keep cool, dudes!!!
Let me clarify my stand on JC lecture materials and the Copyright Act. The Copyright Act is grossly outdated and some authors have argued for an overhaul of the Copyright Act in US in the internet age. With Google and Coursera, my idea is that if every JC puts its lecture and tutorial materials on the website(s) for all to view, students' standards should theoretically be raised. I feel that knowledge should be shared and collaboration is the key to success in the 21st century of uncertainties and seismic changes.
You may desire to analyse the trends in the Cambridge papers of 2010-2018, as your teachers may set questions that are similar to the papers in the prelim exams.
Set goals for what we want to achieve this year. Set your sight on greater things! Most of your parents and teachers have prepared you well for education, and the rest is for us to overcome hurdles! Next is to be consistent in little things. Your daily habits will determine what your end journey at JC will be. Have an overcoming attitude! Let us be strong!
An important thing is to grasp the gist of every lecture and tutorial.
You may like to do some physical exercises to prepare yourselves for a challenging year ahead! Also, Being emotionally healthy, eg. not bearing grudges, does help you indirectly in studies as you can concentrate better in studies. Do not worry, be happy!!!! :-)
You can do it! You can surmount the barriers and fly as an eagle! Your dreams can come true!
Do plan your CCA activities well, as CCA records are needed for entry to universities and some faculties need good CCA records. Well, it is not just points and grades in CCA. More importantly, is to have passion in your CCA and not just go through the motions. We only have one life, so live it well and to the fullest. :)
What can you do for chemistry? Do you still like chemistry and your chemistry teachers? One important thing is to befriend chemistry and like chemistry and have some passion for this subject, even if you may not touch it the rest of your life after A levels.
A good way is to make your own notes, or at least underline your notes. Some of my students draw cute cartoons here and there in their lecture notes....
All the best! Network with your classmates. You are bound to need help from them at some point or another. Life is mostly about treasured relationships. Grades are not everything.
Time management is crucial in this hypercompetitive education system.
If your school has not finished the entire chemistry syllabus in mid-May, you may want to read ahead so that you could be adequately prepared for prelim 1 and prelim 2 exams. I know life is very stressful in JC, and this is the price we have to pay for having one of the best education system in the world. So play the game, pay the price and you will be amply rewarded. If you start studying only in Jun, it may be too late. This is a reminder, and a gentle one! (From one who has seen at least 1000 students go thru this system).
Anyway, how does one measure success? In terms of money, status and power? Is that the right way of measuring people? This question begs a debate. Our Singapore system may have too narrow a definition of success.
The bar for tests and exams has been raised. But say you can! You can! You can! Just do it!
We can learn from sports psychology. Joseph Schooling, the great Singapore swimmer, psyches himself up before every race. So, similarly this A levels assessment is also a mind and psychological game. Even if the exam is tough, psych yourself that you will be tougher than the others. You have the resilience. Confess good words. Declare yourself a victor and celebrate (a little) victory even before the exams is coming. Being emotionally healthy is highly important. Inject yourself with doses of good and inspirational words : "I will conquer! I am a victor!"
For those who are a little knocked down before, get up. It is time to get up. Time is precious. Redeem the time. Get up! And keep fighting! Surround yourself with positive people! It is a mind game. Get up and start fighting. Like a boxing match, the one who lasts the longest and is not out of the ring wins. Get up!
There are motivational books and inspirational websites. Get your morning happy. Mornings are the most crucial moments of the day. Get yourself psych up. You know the methods yourself.
Some students sabotage themselves by telling themselves subconsciously they do not like a particular subject. It is no wonder they do not excel in the subject. Excellence begins in the mind-set and paradigm. You can do it.... Just do it.... And do the right thing....!!!
If you can finish many of 2018 prelim papers of JCs, the chances of you getting an A or a B may be higher. It is all about making few mistakes in exams and getting the right answers for the examiners that matter. Interpretation of question is an important key to scoring in the exams. We need not be long-winded in our answers. (You may find me super-duper long winded, haha....)
You may want to purchase Organic Chemistry Summary booklet and Physical Chemistry Summary booklet (now on sale in Coronation Plaza at $8 each) by Mr Pang Peng Cheong and Mr Sam Lee; or do summary reactions for each functional group in organic chemistry.
******* Understanding chemistry is not to memorise the whole chunk of notes. Smart students ask themselves what the concepts are: eg. electron flow, arrow pushing, guessing which gases or other products are generated in a chemical reaction (smart guess), summarizing notes in their own words. Some students think of wacky short-cuts to help them remember concepts. (Thanks, Adam Khoo LTG!) Also, a visual learner may use a lot of highlighter and mind-maps, diagrams, tables and charts and summary of reactions and their reaction conditions to help them remember.
One of my students who was hungry for success remembers by keywords and association (neuroscience technique). Ask your smart classmates for some tips. Be nice!
A very useful advice from rsc.org (a chemical society) for tackling Paper 3 of Chemistry exams:
"Some of the questions will contain material you will not be familiar with.
However, by logically applying the skills you have learnt as a chemist, you should be able to work through the problems. There are different ways to approach the tasks – even if you cannot complete certain parts of a question, you may still find subsequent parts straightforward. "
*** For those JC2s who are really struggling in chemistry, please try to get your foundational topics right. Ask for help from your classmates. You may also want to seek help from tuition centres or private tutors. Please start to revise now! Time and tide wait for no man!
Confess good words and positive thoughts.
Religion is a powerful force. Those who are open can seek help from the Person Upstairs.
It is my pleasure to serve you all in these blogs.
All the best for your future endeavours!
For tuition enquiries, please sms/ whatsapp Mr Chong at 82875873 or email him at firstname.lastname@example.org
Here are mine:
A-level Chemistry by Ramsden
Chemistry for Advanced Level by Peter Cann and Peter Hughes
University Textbooks :
Organic Chemistry: by John Mcmurry (9th edition)
Organic Chemistry: by David Klein - 3rd edition
Title : Organic Chemistry (2nd edition)
Authors : Jonathan Clayden, Nick Greeves, Stuart Warren
Publisher : Oxford University Press
(This is a tough book to handle)
General and Physical Chemistry:
Chemistry3 by Burrow, Holman, Parsons, Pilling, Price
chemguide7 aka Mr Chong
B.Sc(Hons), Dip in Education
E-mail: chemguide8 at hotmail.com
HP : 82875873
God bless you!!
P.S. The more you are exposed to chem concepts, the more you understand the paradigm of the scientists. Make chem a delight, not a duty or a chore. And you will score well. Be curious! Do not worry, even if you do not read any of these topics, you can still keep cool in exams and solve the problems. You just require more thinking on the spot!
You may use wikipedia to read more about the topics mentioned above.
# Mr Chong is not responsible for any inaccuracies or the topics he highlighted that do / do not appear in assessments. Chem knowledge is vast and examiners have a large scope to test for in exam papers.
God bless you!!