* Tips for 2025 O Level Chemistry Students

[Updated in 2025]

Hi all, 

Welcome to my international Chemistry blog..

 :)

 

You are free to look around and find information that you may use in your course of study. My O and A levels Chemistry blogs have hit more than 1 million pageviews. Thank you readers for your support!! I am so happy and humbled by this experience. I am honored to serve you as we continue on life's journey..

 

For 2025 Secondary 3 students under the new Chemistry syllabus, students may wish to get a hold of the older Chemistry Matters 2nd edition written by Tan Yin Toon, because the latest 3rd edition textbook by Marc Chang and other authors, is not written as rigorously as the 2nd edition. Students may like to refer to the 2nd edition Chemistry Matters textbook if the explanations in the 3rd edition are not lucid. Students who read the latest Chemistry textbook may like to read it when they are on a full stomach, because this textbook has many references to food.

 

For 2021 Cambridge exam papers, Section B of Paper 2 was filled with questions that have A level chemistry concepts tested. So 'on the ball' students may ask their private tutor to introduce some simpler A level chemistry concepts and questions after the students have done many prelim papers and ten year series exam papers.

For 2019 Cambridge exam papers, Paper 1 was generally tedious and tricky

The standard of many questions approached that of top school prelim papers. This implies that teachers may set tougher questions in Paper 1 prelims exams this year. A few of the questions border on A level chemistry syllabus.

For Paper 2, the first question on polymers was to distract the students. It was an unexpected question and tested on the obscure area of polymers which many teachers rushed through for organic chemistry. It specifically tested on the polymers that were used for clingfilms and fishing line, which may have caught some students unaware. The rest of the questions were quite all right but some parts were testing on obscure parts of the syllabus. For Paper 2 Section B, B8, B9 and B10 either questions required some A level chemistry knowledge. Many students may have difficulties answering these questions. It looks like teachers may set more difficult school exam papers this year.

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For 2018 Cambridge exam papers, Paper 2 Section A was manageable. Paper 2 Section B was highly atypical. Flame emission spectroscopy and ion chromatography appeared in the first question. Flame emission spectroscopy is in UK Cambridge Edexcel syllabus. Usually spectroscopy is learned in A levels or university chemistry, but Cambridge has simplified the question and made it to appear in O level Chemistry exam papers. Ion chromatography is covered in university chemistry but it appeared in O levels exam papers. Some parts to the questions seemed ambiguous. Students have to keep calm in the exams and apply their existing knowledge of chemistry in a new context.

The second question was on triglycerides. Triglycerides are fats or lipids and this class of molecules seldom appears in A level Chemistry and is encountered in university biomolecules module or Biochemistry subject. It was not an easy question and it required the application of the chapter on esters.

.The rest of Paper 2 Section B was more manageable.

  For the combined science students, based on last few years' exam trends, the examiners may set tougher questions for the physics section of the science papers rather than the chemistry section. So all chemistry fearing students you'll be having a bit of leverage there.

 
If you have a private tutor, you may want to ask him/her to provide you some basic A level questions that are relevant to O level pure chemistry syllabus for you to try. This is because Cambridge examiners have recycled A level questions in last 2 years exam papers. You may like to start trying tougher questions starting from May 2024.

 

For those who aim to have a good grade in Chemistry, some may need to finish at least 10 prelim papers, finish the entire ten year series and read some basic A level Chemistry notes. But most students are not willing to do all these because of the price one has to pay. 

  
So it looks like the standards of O level Chemistry exams this year in 2022 may be raised again. So students are advised to prepare for the basics and a little of A level materials so as to up their grades.

 

If you have tuition with me, if you are not ready to do the extra optional topics mentioned in this article, I will not do them with you. Instead, I will impart the basics of chemistry to you. 


So do not worry. I can customise the tuition to your own needs. 

Do you know the name of the precipitate in Qualitative Analysis when aqueous ammonia (please do not use the old name of ammonium hydroxide) is added to lead (II) ions? When excess aqueous ammonia is added to lead (II) ions, the white precipitate is insoluble in excess.

Answer: lead (II) hydroxide.



You can ask your tutor to explain to you the terms:

1.      First ionization energy

2.     first electron affinity

3.      atomic radius (a question came out in Singapore-Cambridge papers in 2014)

4.      ionic radius,

5.     electronegativity which is in the A level syllabus

6.     Atomic structure and periodicity chapters (extension of Periodic Table chapter in O level syllabus)

You may want to ask your teacher what are the products when chlorine reacts with sodium hydroxide at low temperatures and high temperatures. This came out in Cambridge papers. Cambridge likes Group 17 or Group VII elements in O and A levels papers.

 

Your teacher may not have taught flue gas desulfurization in the chapter of air and atmosphere. So please learn it as there is a little chance that it may come out for exams. 



You may want to ask your teacher to teach you about Maxwell-Boltzmann Distribution graphs for the chapter of Speed of Reaction.

You should also google on it or read some A level textbook in your library (is your library well-equipped or just for chit-chat, Lol!!!!) A little of A level stuff is sure to come in O level exam this year.


You may go ahead and study transition metals, carbon cycle (Maintaining air quality ), how Chlorofluorocarbons interact with ozone layer (air chapter) cos these are in the current Sec 3 syllabus.


Organic chemistry is important, so study it properly, please. Please note that each carbon atom forms four covalent bonds. All my students make these mistakes when drawing the full structural formula of organic molecules.


There is a slight addition to the O level chemistry syllabus for Sec 3 students.  The standards of the sample questions have been raised. So, be prepared that tests and exams this year will be more difficult than your seniors, especially in top schools. 

Anyway, take school with a pinch of salt. Those who do very well in society later on are usually not the ones who did very well in school in their teenage years (maybe except for scholars). Money-making, enterprising spirit and academic excellence are two different talents.
   

 Now may be the time for you to settle into the daily timetable. Set goals on what you want to achieve this year. Have some dream about the future courses you want to take and CCAs plus hobbies. Next is to be consistent and challenge yourself to greater heights. 

Cool right? Give me a high five... yeah.

If I were you, I would be attentive in class. Many adults regretted they should have been more proactive in school.

Network with your schoolmates too!

As an educator, how I wish I could make you fall in love with chemistry!!! Chemistry can be quite fascinating, it is just that it is not easy to teach this subject and many teachers have made it a dry and monotonous subject. The planet Earth and life itself are made up of the strange and bizarre world of atoms, molecules and ions.

You can use analogies to learn chemistry. It is a powerful way of learning chem. Much of chemistry arises from electrostatic forces of attraction between the ANIONS and the CATIONS; and more fundamentally, the highly powerful and short-ranged attraction of the electrons for the protons. BTW, you can visualize the movement of electrons to be like bees buzzing around the bee hive - unpredictable, a little random and jazzy and very speedily (imagine a F1 ferrari car).

So the story of chemistry can be said to arise from a simple concept that "opposites attract, similar repel". Cations like to attract anions. 

 

We can make chemistry fun and happening, rite??? Anyway, our bodies are made of billions of water molecules swimming and zapping around the cells (oops, that is biology already).... And cells produced many biochemical reactions per second in our bodies. Our bodies are wonderfully made!!!! Lol.....


Fun, indeed! We can make stories in our learning and make some concepts ridiculous so that we can remember better.
   
All the best and God bless you!!

Mr Chong
Private Chemistry tutor
ex-Sec School and JC teacher
B.Sc(Hons) in Chemistry, Dip. in Education (PGDE)