" May you enjoy Chemistry as your very own - ie. make it something you truly own for yourself, and don't regard Chemistry as something instructed to you by any external source, eg. school teachers; respect yourself as your own Master of Chemistry. Only with self-ownership and self-love, will self-motivation and self-excellence come naturally."

- Mr Heng (BedokFunland JC) aka UltimaOnline

Stressed by school? Then you will want to come for my Tuition!
 

Parent / Student : "(My son/daughter is) / (I am) already very stressed with all the homework assignments from school. I don't know if he/she/I can tahan any more stress by having tuition!"

Mr Heng : "My Tuition is here to help reduce your stress, not to give you more of it! If you're unable to understand your Science teacher in school, inevitably you're going to be stressed. I'll help you understand your Science, at your own personal pace, something your school teacher cannot do (as he/she has to handle an entire class at once). If you're stressed and overburdened with homework, simply bring your homework assignments to our tuition sessions, and I'll help you out with them (I'm not going to do your homework for you, of course; instead I'll help you to understand the questions, the relevant concepts involved, and I'll guide your problem solving process and check your answers). Remember, my Tuition is here to reduce your stress and help you enjoy your subject!"
 

Greets!

Thank you for visiting my webpage. I'm Mr Heng (Chemistry), and my mobile phone number is 8189 4871. I'm a full-time Chemistry Tuition Teacher offering tuition services to 'A' level and 'O' level students, as well as Integrated Programme (IP), Advanced Placement (AP) and International Baccalaureate (IB) students. All tuition sessions held at my place of residence in Lagoon View (between Bedok and Marine Parde).

I am a former Ministry of Education (MOE) Teacher, and have over 5 years of experience teaching Chemistry at a local school, before I resigned several years ago to become fully self-employed. I hold a Bachelor's Degree in Science (double major) and a Diploma in Education. And because I love teaching so much, I've now continued doing this in the form of tutoring! :)

My father, (Mr Heng Hwa Heng), a retired MOE-teacher who taught Mathematics for over 40 years at various Secondary Schools and Junior Colleges, holds a NUS degree in Mathematics. He has authored and co-authored a number of Mathematics books (assessment books, guide books, and a textbook) at the Secondary and JC levels. He also served at MOE HQ for many years.

For Mathematics tuition ('A' Levels / 'O' Levels) from my father (Mr Heng Hwa Heng), please contact him directly (his handphone is 8138 1168) to inquire on his tuition fees rates per session and/or slot availibility. His Curriculum Vitae may be viewed *here*.

All Tuition sessions are held at my place of residence, at Blk 5000M Lagoon View, located between Bedok (Temasek JC) and Marine Parade (Victoria JC). Please note that all fees must always be paid in advance on the 1st session of every 4 weeks.

Group Tuition is significantly less costly but can be just as effective (note : Individual Tuition is possible if requested, but will be double the fees compared to group tuition; see my rates below), and there are also other advantages to small-group tuition and is thus recommended.

For new Group Tuition students, please form your own new group (ie. with your own friends / classmates / schoolmates with compatible schedule; minimum 2 students).
 

See my list of 'A' Level distinction (A grade) students here.
 
 

(Below left & right : Deborah Tan CJC; Iris Ng TJC, 2009)
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. (Below) Peter Ng Chee Yee, one of my ex-Tuition students (2007)  is also a most talented and passionate pianist - click on his photo below to watch him play his self-arranged beautiful rendition of Pachelbel's Canon.

Peter Ng Chee Yee (TPJC 2007), playing "Peter's Canon". Click image above to view video.
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My students during tuition
(Above left to right : Peter TPJC; Andrea, Max and YuanWei SRJC, 2007)
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My students with our BedokFunland JC Mascot "BearBear"
(Below left & right : JaiLing VJC; WanPing VJC, 2008)
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"I recall times (very often, actually) when the principal gave hour-plus-long speeches (no exaggeration) during daily morning assembly period, and when he was finally done, he always received tremendous applause (sometimes a standing ovation) from all the students (because they were tremendously relieved the speech was over) and indeed (applause) from a number of (us) teachers as well. Incidentally, the principal always believed the tremendous applause was for his (self-believed) brilliant oratorical skills, and always enjoyed the applause."

1) On the problematic Organic Chem question (Paper 3), the selective reduction of only 1 of 2 nitro subtituents on the benzene ring :

There is but 1 way to reduce only one of two nitro groups present (with a high yield), is to use a reagent not taught within the H2 (or even H3) syllabus.
 

This reagent is sodium sulfide - http://en.wikipedia.org/wiki/Reduction_of_nitro_compounds

It's unlikely that the SEAB-Cambridge guys expected you guys to know this reagent, it's more likely that they didn't care about the yield, they just wanted to you to suggest a possible synthesis pathway, no matter how low the yield.

Since this commercial compound exists, there had to be a better (ie. higher yield) pathway for its synthesis. It turns out to be the one involving sodium sulfide. Evidently, SEAB-Cambridge in setting the 2008 H2 Chem paper, thought it would make for an interesting question to use this compound (they didn't care that students would be confused and frustrated by the mysterious selective reduction) and went ahead to ask for an unrealisitc 2-step synthesis pathway, in spite of the fact that sodium sulfide reduction is not taught within it's syllabus, and without such the selective reduction of only the ortho nitro group would result in a pitiably low yield.

I discussed this problematic question on a dedicated Chemistry forum.

kiwi wrote :
>>> from memory sodium sulfide reduction of dinitroarenes stops at mononitroanilines, but you wouldn't be expected to know this for a-levels <<<

macman104  wrote :
>>> I'm in my 4th semester of Organic Chem in the University, and never once have I heard of that reduction (although, some sort of reduction by Na2S does sound vaguely familiar from a lecture, but only briefly).  Apparently it is called the Zinin Reduction, and is pretty old chemistry (with the initial info published in those old German journals, ~1842).  I found an old text relating to it, I've uploaded the PDF for you to see.  At the end of the 3rd page, they mention the selective reduction of di or tri-nitro compounds. <<<

I replied :
>>> Thanks to both of you for taking the time and effort to check out on this. Much appreciated. The Zinin Reduction is obscure, for sure. I couldn't find it in any of my (half-a-dozen) Organic Chem texts, and finally found a mention in pg 1817 of "March's Advanced Organic Chemistry, 6th Edition".
Online search reveals similar obscurity :
http://www.answers.com/Zinin%20Reduction
Well, point proven. MOE-SEAB-Cambridge must think it most amusing to annoy 'A' level (H2 level) students with this question (which is impossible to answer within the context of their limited syllabus). <<<

macman104 replied :
>>> No problem.  And right, ONE part of a page in March.  Not really something you might just browse across (does anyone even "browse" March for fun? lol)...
Anyway, glad the question could be answered, but truly an unfair question I believe. <<<

kiwi replied :
>>> No problem. March - is there anything it doesn't know?... <<<

Click here to view the ancient chemistry journal that describes the Znnin Reduction :
http://infinity.usanethosting.com/Tuition/ZininReduction.pdf
 
 

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(Above)  Wee Wen Shih

. Useful for quick search of names, formulae and structures of compounds .

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Recommended 'A' Level Chemistry Books
(Available from Popular Bookstore, authored by CS Toh, Step-by-Step publications)

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The Periodic Table

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The Ultimate Periodic Table
(An excellent buy; use debit card to purchase from Amazon)

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Standard Redox Potentials

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Greek Alphabet Symbols

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Visit my main website page here

Visit my Pachelbel's Canon webpage here