Hi everyone,

Geese…It’s been a while since you last hear from me in this GCE O Level Chemistry blogsite. During this period, i have received more than 50 emails and Facebook messages from students, parents and educators (teachers & tutors) locally as well as globally e.g. US, Uk, Pakistan, Mauritius, Indonesia, Australia, Malaysia, India, Brunei, etc.

Many questions were raised (besides the Chemistry Questions) on my whereabouts and safety:

Hi Sean, is everything alright with you? It has been a while since we see you blogging on www.SimpleChemConcepts.com. Hope you are fine. God Bless.

Hello Sir, i recently subscribed to your chemistry newsletter and the regular chemistry tips helped me to pass my chemistry test. Thks very much =) . Your sharing of chemistry every day life examples has also build up my interest to learn Chemistry. But i realised you have stopped blogging for a while? Are you ok?

Mr Chua, how come dint see more chemistry tips and exam strategies from your blog anymore? You stopped sharing your knowledge via blog already? You went to university to teach chemistry full time or went back to work with your scientists friends?

Hi Sean, my daughter is unable to join your Chemistry Coaching Programme due to heavy involvement in SYF and CCA in schools? I got her to subscribe to your chemistry website, and she told me that she uses your website to study for her recent common test. She has yet to show me the results, but this is the 1st time i see her studying Chemistry! She hates Chemistry last year in Sec 3! Thank god for having you sharing graciously to help students that are academically challenged. I have personally been reading the category on Chemistry Phenomenons & Videos and found them very exciting. Is something wrong with your website recently? We did not see any updates from you. Btw, i will contact you in April with regards to my daughter’s coaching when she has more time.

I would like to take this opportunity to thank all my blogsite readers that have shown their concern about me. I realised that i have made the correct decision to spend time writing this Chemistry Blogsite (GCE O Level Chemistry) to share my knowledge with chemistry students, parents and educators globally. =)

Now, here is the REASON why i have MIA (Missing-In-Action) for the past 2-3 weeks:

Reason # 1

SimpleChemConcepts.com has been undergoing construction since 3 weeks ago in order to serve the readers better.

(phew….together with my programmer/designer, we have been really busy “re-constructing”)

I am doing my best to categorise the information here into easy-to-find sections so that you readers can find a specific chemistry chapter/topic easier. My programmer/designer is based overseas and due to time differences, we have delays in communicating ideas across borders smoothly.

In fact, i have been blogging every 3-4 days, but there is this technical glitch that does not allow me to publish my blogposts in my website [Yes..i have about 5-6 blogposts that are stored as drafts right now..will slowly release it to you so that it won't fill up your email inbox (for our F-R-E-E newsletter subscribers)]

Reason # 2

I have been busy for the last 2 months with the following: (more…)

Chemistry

SPA Tips

Over the last few days, i have received a number of emails and Facebook messages from O Level students for School-Based Science Practical Assessment (SPA) on:

• Possible questions that may be asked in their SPA
• Common errors that they need to be aware of in SPA

I did a check with several schools and found out that this week (9th March – 13th March) is designated as SPA Week for many schools.

SPA is considered as Paper 3 of your O Level Chemistry Examinations and involves a set of teacher-assessed practicals spread over the two/three years of your O Level course. It usually consists of a series of examinable practicals that are spread across your O Level course, with a total of 48 marks – Impt: this makes up 20% of your final O Level Chemistry Examination in terms of weightage.

Since this is a “teacher-based Science Practical Assessments”, the teacher-in-charge will assess students based on the students’ behaviours as well as their experimental techniques in the laboratory (besides your final answers in the practical sheet).

An example of a marking scheme by your teacher-in-charge based on Skill Levels 1 (Easiest) – 4 (Toughest):

Lets check out a potential question on Acids, Bases & Salts from Skill Set 1 (Easiest):

SPA Title: To prepare a soluble salt

Aim: In this experiment you will be assessed on your ability to follow instructions and use apparatus safely

Description:

A soluble crystalline salt can be prepared by the action of a suitable acid on an insoluble metallic oxide or metallic carbonate. The salt can then be purified by crystallisation.

In this experiment, copper(II) sulphate is prepared by the reaction of copper(II) carbonate on dilute sulphuric acid. The equation for this reaction is as follows:

CuCO3 (s) + H2SO4 (aq) –> CuSO4 (aq) + H2O (l) + CO2 (g)

Procedure:

1. Measure out 30 cm3 of sulphuric acid into a beaker.
2. Warm the acid in the beaker until the temperature of the acid is not more than 50 oC.
3. Add the copper carbonate powder to the warm acid, a little at a time, with stirring, until all the acid is used up.
4. Pour the mixture into the filter paper in a filter funnel. Collect the filtrate in an evaporating dish.
5. Evaporate the filtrate. Stop heating when some crystals start to form on the surface of the filtrate or at the side of the dish.
6. Allow the saturated solution to cool slowly.
7. Pour off the liquid from the evaporating dish. Dry the crystals between a few sheets of filter paper.

Marking Scheme:

• Use of appropriate measuring cylinder to measure the volume of the acid.
• Use of appropriate apparatus (glass rod/thermometer but gently) to stir the mixture.
• The hot mixture was poured into the filter paper without spillage/overflow.
• The acid was allowed to cool (check that student reads the temperature of the acid before adding copper (II) carbonate).
• Copper (II) carbonate was added into the beaker, a little at a time, with stirring and without spillage.
• The carbonate was added until no more dissolved/no more bubbles were seen.
• Filtration was properly done (filter paper was folded properly; no prodding of filter paper in funnel; check that filtrate is clear).
• Flame was turned off when the filtrate was saturated (saturation: when crystals appear on the filtrate surface/at the side of the dish).
• Proper control of the flame when filtrate was being evaporated to prevent spluttering. [Safety]
• Goggles were worn. [Safety]

Last & Most Important Tip:

This is a “teacher-based assessment” examinations:

Students: no matter how playful you are – try NOT to STEP onto your teacher’s toe during your SPA period…ssshhhh….hope you get my hint/tip…

Parents: Do remind your child about this important point…

Teachers: Let’s help these students to have a long-lasting interest in Chemistry…

PS: Check out archives (previous blogposts) related to SPA/Chemistry Practicals HERE

PPS: Drop me a message in the “Comments Section” below. I would love to hear from you.

I understand there are a group of private candidates that are following this Chemistry Blog very closely in Singapore.

Just a quick note:

2009 GCE N, O and A Levels Examinations are open for registration for Private Candidates.

(From TODAY newspapers 6th March 2009) [Click Image for clearer view]

If you are studying in private schools right now, your school should be taken care of this

If you are re-taking your N, 0 and A Levels as Private Candidates (home-based or studying in other Polytechnics, etc), you would need to register for it.

Last week while i was taking the Mass Rapid Transit, i realised that you can Register for your N, O and A Levels as Private Candidates using modern technology – you can use S.A.M Machine! at your convenience.

[Click Image for clearer view]

All The Best!

PS: Drop me a comment if you are a Private Candidate. I would love to hear from you.

Hi Students (both GCE O Levels and IGCSE),

Mole Calculations has been the #1 Killer topics for many Chemistry students. Is it yours too?

Back by Popular Demand, i am glad to announce that Mole Calculations Mastery Workshop 2009 is back!

>>CLICK HERE for Mole Calculations Mastery Workshop 2009<<

Mole Calculations, or commonly known also as Mole Concepts or Chemical Calculations is a concept which is so important that it is tested in every Chemistry Exams blended in ANY type of question, yet many students are lacking the essential understanding of how to score in this area. Are you one of them?

Now, if you want to score more marks for your Chemistry tests and exams, read on!

I will be personally coaching a group of students in March to master EVERYTHING you need to know in Mole Calculations.

Check out this video here quickly to find out how much you can benefit from this workshop. Click here for the link to video if you are unable to watch it below directly.

Early Bird Price Registration starts! Enjoy early bird discounts & 3 bonuses (worth S$697)!

>>CLICK HERE for Mole Calculations Mastery Workshop 2009<<

(more…)

After communicating with several students, i realised that many come to his Chemistry blogsite to look for more F-R-E-E O Level Chemistry Questions and Solutions/Answers. In fact, you can find them at “Chemistry Notes & Tips” under CATEGORIES on the right hand side column of this blog. Seems like many students are not sure how to find the topics of their interest.

I have decided to put up a “NAVIGATION VIDEO” on this blog to teach all readers how to maximise their learning in this blog. Stay Tuned for it!

Meanwhile, if you are looking for specific O Level Chemistry Topics, check the following links for wealth of information and tips:

• Atomic Structure
• Kinetic Particle Theory
• Bonding & Structural Properties
• Balancing Chemical Equations
• Mole Calculations
• Rate of Reaction
• Periodic Table & Group Trends
• Energy Changes
• Redox
• Electrolysis
• Metals & Reactivity Series
• Organic Chemistry
• SPA / Chemistry Practical Tips

Hope this helps you in learning Chemistry and (more…)