Chemical equilibrium, denotes a reaction condition established when it’s a:

1. Closed system
2. Reversible reaction
3. Dynamic (no visible change, but reaction happens in microscopic level)
4. Rate of forward reaction = backward reaction (rate of forming products = rate of product dissociation)

You have searched for most common equilibrium processes last week. The ones you must really nail are these two processes:

1. Haber-Bosch‘s ammonia synthesis
2. Contact process of manufacturing sulfuric acid (why is it named ‘contact process’?)

The above processes are not all consist of equilibrium reactions. Only ONE reaction for each process. Make a note of which reactions they are and the condition (pressure, temperature, catalyst). (psstt… these are usually the conditions asked in your test).

The conditions stated for the manufacture are the optimised ones. Means they may not give the most abundant product, but they are a good trade-off between good yield and cost of process. Very high pressure may give the most gas product yield, but it will be very expensive on maintaining the pressure and more dangerous for the plant’s workers.

Optimisation, or getting the most suitable compromise, works by shifting the equilibrium. Just like when you’re climbing on an escalator that’s moving down. In order to stay in a certain height, you must climb with the same speed as the escalator, but in the opposite direction. And when you want to go to a new height and stay there, you must climb faster first. Then, when you have reached the new height, you will have the same speed as the escalator again.

This works the same with equilibrium reaction. When equilibrium state is reached, the reaction is dynamically stable. Means, it can change. By changing pressure and/or temperature, you can set the reaction to a new equilibrium. The reaction will then move faster toward forward (or backward) position, then stays there in the new equilibrium state. This change of equilibrium state is what we call EQUILIBRIUM SHIFT.

Equilibrium shift works on Le Chatelier’s principle (he’s a French, so make sure you pronounce it right). Make note on what will change equilibrium position (factors affecting equilibrium) and what the effects are. [if you have done this in your last week's task in library, it will not be something new for you]. “What will happen if you raise the temperature, will you get more or less product?”, for example.

There could be specific terms on when the factors are NOT applicable. For instance, you can’t shift the equilibrium position of reaction if all the reactants are solid.

Your task would be working on the ‘Latihan 4.2′ in your Kimia 2A Erlangga book. To make working on it easier, understanding the ‘Uji Kepahaman’ questions 4-15 will help. Should there be any difficulty, you can ask here or you can always mention me in Twitter through @litachem.

Tweet you later, kids!

Here are worth websites to visit on equilibria (don’t say I didn’t tell you):

• Chemical Equilibria on ChemGuide.
• Revision note (summary) of chemical equilibria on Docbrown.
• Equilibrium animation on Wired Chemist. (this website is visually helpful)
• Equilibrium interactive animation by Pearsoned.
• Flash-based animation on Haber Process. You can change the P & T of the process and see how much will you get.

Dear fresh brains of XI and XII grades of SMA 8 Jakarta, I welcome you to my chemistry class *grin*. A different level could disarm everything you have known, as if you didn’t learn anything relevant last year. Worry not. It’s just a symptoms of holiday. Or so we hope, for your good sake.

Here is my take on how we supposed to learn: using our brain, in terms of utilizing our gift, SENSE. You might feel uneasy when I pushed you with questions that you didn’t care what the answer is, moreover you think important for your life. Guess what, you may not get ANYTHING useful for your life during high school, IF you resist to learn using your mind. Drown in misery of uselessness you may say later.

But I should remind you this: learning is YOURS. Learning is not listening, or doing homework, or memorizing formulas, or quick calculations. Learning is what you get and use in your life, after you depart from school gate. Could be the very day, or years after. It’s how you take & deliver things, not only the subjects themselves.

So whether you learn something or not, it’s your choice. I choose to take chemistry into my life & use it on daily basis to make choices. What’s yours?

You may find these files helpful for you. I downloaded them from the internet. So the right’s keeper is their creator. Any permission should be addressed to them. Please bear in mind, for nomenclature, this could be different from our National Curriculum. Be aware of what’s expected from you in your current curriculum.

A2-Organic reactions spider diagram

Rules on Drawing Structures

Nomenclature & Isomerism

Organic Mechanisms

Syllabus, of course.

This will be the guide of your A-level course. Targets which should be completed, what’s what (define, describe, explain, suggest), details, changes from previous syllabus, and at the end of the syllabus: Data Booklet. You need to get used to this one since this is the helpful tool for you instead of writing tool and calculator.

If you’re XII graders, you will still be using 9701_y10. If you’re XI graders, you will use 9701_y11. Download it here.

Revision checklist.

What? Study guide? Well, no, I don’t use it. There’s revision checklist for you to check your progress. Download it here.

A-level Science Applications Support Booklet

This booklet talks about applied chemistry and a bit about biochemistry. All A-level (A2) Chemistry candidates MUST have and study this one as a starter for your exam preparation. Good for others as advanced knowledge, too. Download it here.

Here are the name list of XII-Science students. Sorry I only took the science class list home. You can see all the list (for XI graders, too) on the announcement board at school.

XII-Science-A

Homeroom teacher: Lita Mariana

1. Alex Beny K. –> chairman
2. Alysha Athia
3. Arief Dimas Dwiputro
4. Cindy Dessidia Gamal
5. Danaparamita Hapsari –> secretary
6. Dimas Wahyu B.
7. Dina Rahmatika
8. Dini Mardhiyani
9. Diva Magistee
10. Dwinia Emil
11. Khalda Az-Zahra
12. Michael
13. Nadilla Fedriany Soenardhi
14. Nisrina Nur Amalina
15. Pramesti Istiandari
16. Ryan Adriansyah
17. Ryandanu Priwanta
18. Soefiannagoya Soedarman
19. Widya Hayu Lestari

XII-Science-B

Homeroom teacher: Yustrida Maisa

1. Alifiana
2. Aninda Fariza
3. Aulia Rahman Anshary
4. Centane Onanda Nasri
5. David
6. Dinda Larastika Riyanto
7. Dyah Astri Paramaramya
8. Eleny Marsha Claudia
9. Ephraim Deviaro G.
10. Evellyna Meilany
11. Hakim Cahyodewanto
12. Karina Dhaniarti
13. Muhammad Irfan Perdana
14. Naufal Elang Ciptadi
15. Navintya Cesvini
16. Putri Widya Utami
17. Rifina Ramdhiantri Rahisa
18. Zara Juliana

XII-Humanity

Homeroom teacher: Dewiyanti

1. Alifia Nuril Ikrami
2. Allinka Ilmarani
3. Emir Hanniverano S.
4. Ghaisani Shabrina R.
5. Gregorius Bramantyo A.
6. Hartantio
7. Lintang Tunjung Manik
8. Nadia Hanani
9. Reza Fadli Rizkianto

Guidance & Counseling teachers

XII Science A & B: Priadi Tri Handoko

XII Humanity: Sri Hartatik