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Group vs Private Tuition

Mr Khemistry

Group vs Private Tuition

No matter whether you’re a student or parent looking for tuition for your child, this question undoubtedly popped into your mind.

So what are the pros and cons of each and which is more suitable for you? Read on to find out…


  • Follows a set topic schedule.
  • Limited interaction during lessons.
  • Timings are fixed, lessons usually cannot be rescheduled.
  • Cheaper compared to private 1-on-1.
  • Group dynamics allows for student discussions and learning.
  • Likely to have customized notes.


  • Flexible timing according to mutual availability. Lessons can be rescheduled.
  • Flexible topics according to student’s needs.
  • 100{8445fa0408f68c331c03e03f10d6a7bff33fb7168cc52e9b2191ddf5ec3671a6} attention from tutor.
  • Only 1 student so no peer learning or discussion.
  • Usually no customized notes.
  • More expensive compared to  group.

If the student is really struggling badly, scoring less than 30{8445fa0408f68c331c03e03f10d6a7bff33fb7168cc52e9b2191ddf5ec3671a6} in tests and major exams, the course of action is to go for private lessons if finances allows. 

In the event that the student is not doing too badly, > 40{8445fa0408f68c331c03e03f10d6a7bff33fb7168cc52e9b2191ddf5ec3671a6} in tests and major exams, group tuition might work. It is generally not recommended if the student is not motivated to study on his/her own. 

Do call/whatsapp us at 98537960 to let us know if you’re not sure which to go for. 

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Organic Chemistry – Isomerism

Mr Khemistry


Isomerism – What is the difference between a meso compound and a racemic mixture?

A closer look at the terms would already give you a hint. 

A racemic mixture is not chemically bonded together hence we are able to separate the two equal portion (50/50) enantiomers. If we then pass plane-polarized light through just one of the enantiomers, there will be a optical activity.

A meso compound is one that has at least two chiral carbons and a internal plane of symmetry.

meso compound

Hence the meso compound does NOT have enantiomers. Its mirror images are actually identical molecules. So while each chiral carbon will cause a rotation of plane-polarized light, the other chiral carbon will rotate it back, thus resulting in no net optical activity.

eg. in the tartaric molecule above, the top chiral center may rotate the light 5 degrees clockwise and the bottom chiral center may rotate it 5 degrees anticlockwise.

ps: Adding this on to emphasis that the term “meso compound” is actually quite misleading, as it is in fact one stereoISOMER of a compound. Which means the molecule itself might have other stereoisomers (see D-tartaric and L-tartaric acid below) that are optically active!

In conclusion, meso compound and racemic mixture both do not rotate plane-polarized light but for different reasons. Don’t let isomerism confuse you anymore! Come join our classes at Bukit Timah Shopping Centre to hear the detailed explanation!

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How to improve in Chemistry?

Mr Khemistry

How to improve in Chemistry?

Recently i have been reading some personal development books and one of the ideas that came up was how to improve in any area of your life…quite instantly. It takes at most 3 weeks to see significant changes.

Ready for the (almost magical) idea? 

No, it’s not something new. It’s an old principle. “Whatever area you want to see improvement in, track it.”

For example, if you want to lose weight, track your calories. To be more productive, track where you spend your time (hint: social media is a big culprit, emails a close second and meetings third) Want to be healthier? Track how much time you spend exercising. If you want to be more knowledgeable, track the number of books you read. To grow your savings, track your expenditure. 


How do you track? Simple. Write it down. Buy a small journal booklet for this purpose. For a full day. Then two. And three. Then a week. Finally three weeks. Then look at the data. You’ll be surprised that when you observe your own life, there’s so much you don’t know about yourself and what are the things you do automatically or subconsciously. It’s time to snap out of your trance…if you want real change in whatever area that caused you headaches.

Now, if you want to do well in your studies, how should you do it? Not by spending more time reading the notes. 

Practise more. There’s no short-cut. And get your teacher or tuition teacher or your older sibling to mark your work. Track your progress. See what kind of questions stumps you, where do you lose marks, is it calculation or memory work? If you’re not tracking it, how would you know whether what you’re doing currently is working? If you’re reading your notes over and over again with no real improvement in your score, stop doing that! Insanity is doing the same thing expecting different results.


I’d throw in one bonus method, grab hold of a friend who is doing well in their studies, treat them to a nice meal/drink and ask them, how do they go about studying? Or better still, observe how they do it. I’ve had the good fortune to have a friend come over to my place to help me with my weakest subject at A levels. Do you have friends like that? Ask and you will receive, seek and you shall find.

Don’t be like the proverbial lumberjack who slogs away hacking at the tree trunk when all he needed was to sharpen his ax.

Good luck! 🙂 

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Branches of Chemistry at Advanced Level

Mr Khemistry

Branches of Chemistry

Physical, inorganic and organic Chemistry

3 branches of Chemistry

In Physical Chemistry, we mostly encounter formulas and calculations. There is theory but the main applications involves calculations and numerical answers. The most important thing we need to do is to practise. This is similar to Mathematics where you basically have to use the formulas to do calculations for different questions until we are proficient in it. Most students make the mistake of just reading the worked examples in their lecture notes and tutorials. Remember, if you don’t have time to practise it, you wouldn’t do well for it.

In Organic Chemistry, the most basic level is to actually memorise all the reagents and conditions for the different functional groups. A student counted and said it was well over 80. Well, just remembering these reagents and conditions is just the first step. You would need to know how does the different functional groups interchange between each other. A very helpful method is to draw up mindmaps for each of the functional group and combine them to form a massive diagram where you can draw links between each group. It is likely that A level exams requires you to apply existing knowledge of organic mechanisms to solve questions in novel context.

Lastly, for Inorganic Chemistry, you will need to understand how periodicity works, i.e. trends. The way the periodic table is arranged is in patterns. Group I elements all have one valence electron, period 2 elements all have 2 quantum shells etc. After understanding how the trends are formed, you are expected to make predictions based on these trends and state cases of anomalies.

In a nutshell, this is how i see the 3 branches of Chemistry studied at A levels 🙂

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Happy Belated Lunar New Year!

Mr Khemistry

Over the CNY, my family took our maiden flight together back to Sarawak, Miri, to visit my in-laws.

2018 CNY

CNY visitation @ MiriThank God for good advice on how to distract little Felix with munchies as the plane ascends. I had been dreading the flight with this feisty little ball of energy after hearing all the horror stories on little ones screaming their lungs out due to the change in air pressure. I’m happy to say that the return flight was even better as he promptly fell asleep after take off and slept all the way til we reached Changi Airport.

Thank God also for kind parent who gave me an angbao for CNY, i must say, i think it’s the first time i’ve ever received an angbao from a parent…amazing thing is, i’ve only taught her daughter for a month! I must say gratitude runs in the family, my student also gave me a packet of various Japanese finger food:

gift from tuition student

Japanese finger food

Feel super appreciated. I must learn from them to be more thoughtful and show God’s love through my actions. #bekindtoeachanother

Hope you have had a blast during CNY too 🙂

How to improve JC H2 Chem – Part 2

Mr Khemistry

With all the challenges facing the JC H2 Chem students, it’s no wonder many are struggling to do well in the subject. 

Suggested solutions

There are a couple of solutions that might help but these will probably not be implemented anytime soon.

  1. Cut down A level syllabus. And do not re-package additional content with every review. Students do not need more content to study, they need more time to really learn the fundamental concepts! Sadly, this will probably not happen.
  2. Reduce class size. Not likely to happen, ministry would rather merge schools than adopt a more optimal teacher-to-student ratio.

So what’s a parent/student to do? Turn to external help, what else? At A level, it’s mostly out of the parents’ league to tutor the child themselves. So better to look for experienced teachers who are able to guide the students properly.

At Mr Khemistry, we have a good Teacher-to-student ratio to ensure that students get the attention they need. Questions are encouraged and positively reinforced during lessons. And most importantly, time is given for students to take down the blanks before explanation. (Yes, there are still blanks!) 

We give adequate practise for the students to get a good grasp of the concepts tested but not too much until they are overwhelmed. For most topics, there are typically around 6-10 structured questions.

There is also weekly mini quiz on standard kind of question that students need to master. Prior notice will be given on which concept will be tested and it is usually a short 3-4 marks question.

J2 classes also get 10 prelim MCQs to help revise various J1 topics weekly. As usual, worked solutions will be discussed the following week.

If all these are not enough to help the student, ad hoc private lessons can be arranged to help address specific topics that the JC H2 chem student needs help in.

More tips here!

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How to improve in JC H2 Chem – Part 1

Mr Khemistry

How to improve JC H2 Chem

Many parents often ask me, “How to improve his/her JC H2 Chem?”

This question is usually asked by frustrated/hapless parents.

Typical scenario is that the student has studied hard but doesn’t seem to make any improvement. To which a slight probe will most likely reveal that the method of studying basically involves reading the lecture notes.

Over and over.

Interestingly, students sometimes don’t understand what they are reading. But if they don’t understand it, why do they keep reading it?

The fallacy here is that reading something over and over again will help them understand the concept. #fakenews

Reading might help if the concept is explained thoroughly in the notes, with the context, linking from their previous O level knowledge. However, a couple of restrictions hinders the typical lecture notes from being easily understood by the student.

Challenges facing the typical JC H2 Chem student

First, students usually have to fill in blanks in their lecture notes. This takes place concurrently with the lecturer trying to explain new concepts. Most students aren’t too good at multi-tasking. Usually, they choose to focus on filling in all the blanks to revise later. Except that they don’t comprehend what they wrote in the first place! Not leaving blanks for students? Tried that before, lecture theater is nice cosy place to take a nap 🙂

Secondly, lecture notes are meant to be concise and not read like a story. For example, a formula that needs to be applied might just be listed but not derived from first principles. The derivation process helps the student understand how the formula comes about and how to apply it. But instead, the limited space in the notes is used for worked examples.

Thirdly, every subject at A levels has total recommended hours. For the amount of syllabus to be covered, the time given is barely sufficient. Which means that if students didn’t listen AND understand in lecture, they most likely wouldn’t be able to do their tutorials. Which means that they most likely will be doing a second round of copying of worked solutions. Finally when the term has ended, they realised they are left with the unenviable task of reading all their notes and suddenly being able to understand everything. 

Fourth, the number of assessment books catering to the A level student isn’t exactly a lot. It is harder to find practise questions with worked solutions like the O levels. A level concepts are not easily explained in a normal size assessment book.

Lastly, even if they are able to understand everything, there’s another hurdle. Answering exam questions which are definitely much harder than the tutorial questions.

So what’s a student to do? Look at part 2 for the answers!

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How to solve common redox questions

Mr Khemistry


Qn: Sulfur dioxide causes a colour change in acidified potassium dichromate. Given that the potassium dichromate and sulfur dioxide are present in the reacting ratio of 1:3, suggest a likely sulfur−containing product for the reaction.

This is considered quite a common redox question. 

Firstly, what do you need to know? And how to apply what you know to solve this question?

Diagram showing working step

First step

Basic knowledge of common oxidizing and reducing agents. Look up your lecture notes, there should be a table of common O.A. and R.A. together with their respective products. This will allow you to identify which is the oxidizing/reducing agent.

You will also need to calculating the reacting mole ratio between the O.A. and R.A. However, in this particular question, the reacting ratio is given.

diagram showing how to solve redox question

Second step to solve redox question

From the Cr half-equation (you will need to know how to balance half-equations in case they are not found in data booklet), you can determine the number of electrons gained for Cr since you know the product formed. (Note that you will not be able to do the same for sulfur dioxide as you do not know the product form)

Electron transfer is the main concept in Redox.

All electrons lost are equal to the electrons gained.

Diagram showing working steps for redox

Step 3

Once we know 6 electrons are gained by the two Chromium atoms, we can deduce that the three sulfur atoms lost 6 electrons.

Therefore, each sulfur atom would have lost 2 electrons and gained +2 oxidation state. 

Diagram showing solution for redox question

Final step

Since sulfur in sulfur dioxide has an oxidation state of +4, the sulfur in the new sulfur-containing product will have an oxidation state of +6, i.e. sulfur trioxide or sulfate ion.

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How do organic compounds achieve stability?

Mr Khemistry

Important Concept for Organic Chemistry

Organic Chemistry
Two main ways organic compounds achieve stability:








Electrons are delocalized to form different resonance structures, which lowers the energy level of the organic compound. This contributes to stability.

Dispersion of charge

Carbocation is electron deficient while R groups are electron-donating. Thus the more R groups are bonded to the carbocation, the more stable (less electron deficient) the carbocation will be. 

This concept also applies to negative ions, phenoxide ion is more stable as the negative charge can be dispersed into the benzene ring.

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A level Forum Talk @ Popular Bookfest 2017

Mr Khemistry

A level Forum Talk

Took part in the A level Forum Talk at the recently concluded Popular Bookfest. Quite an experience speaking at such a huge venue.

Mr Eric Kua speaking at Popular bookfest 2017

Group photo at the end of the talk

Subjects represented included Maths, Physics, Chemistry, Biology, Economics and GP. Looking forward to more talks, especially for those who have just finished O levels.

For more photos from the event, click here


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