Reaction Kinetics Reaction Kinetics - A team of scientists at Harvard university have built an apparatus which can achieve ultra cold temperatures. This allows them to capture reaction mechanisms previously elusive as they occur too quickly. "Now, they not only performed the coldest reaction yet, they discovered their new apparatus can do something even they did not predict. In such intense cold -- 500 nanokelvin or just a few millionths of a degree above absolute zero -- their molecules slowed to such glacial speeds, Ni and her team could see something no one has been able to see before: the moment when two molecules meet to form two new molecules." Source: https://www.sciencedaily.com/releases/2019/11/191128172339.htm Wow! Scientists are able to actually replicate such ...
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Preparations for A level This seems like a pretty odd time to be advocating students to start preparing for their A levels next Nov. However, winter time is always the best time to prepare for a major expedition. In this time, almost everyone is flying overseas for holidays, we need to start our preparations. What do we need to prepare for? Clarification of doubts for J1 topics as most of them will not be revisited until late in Sept when we are revising for prelims. Even then at that crucial period, there will not be enough time to correct all the misconceptions in the foundation topics. For your information, the pace of lectures will be 1.5 times faster in J2 ...
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MCQ answers B C B C C A D B D D A B D D D A B A A D D C A C B B C C B B The standard for this MCQ paper is pretty easy, there wasn't really any trick questions or questions which are ambiguous. IMO. Only the last question will take a bit longer to calculate, but you should have plenty of buffer from the easy organic questions earlier. Weightage of Paper 1 is 15% so each question is worth 0.5%. Accounting for careless mistakes, most students should score  more than 24 to have a decent chance to score distinction. If you found this useful, do share this with your friends using ...
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Nomenclature of anions One of the common questions that pops up from time to time is how do i write the formula of sodium nitrite? And what's the difference between sodium nitrite and sodium nitrate? Or sodium nitride? This has to do with the nomenclature of anions. The convention for naming anions is as follows: -ide ending is for a monoatomic anion of an element. e.g. hydride, fluoride, oxide, sulfide, nitride, phosphide etc. -ite ending is for polyatomic anions containing oxygen, oxyanions. -ite is for the one with less oxygen atoms. eg, nitrite, sulfite -ate ending is for polyatomic anions containing more oxygen atoms. eg nitrate, sulfate If there's a series of 4 oxyanions, hypo prefix refers to the anion ...
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Suggest Type Questions Firstly, suggest type questions took up 12/75 (16%) marks in 2018 paper 2 and ~24/80 (30%) marks in paper 3. So we cannot ignore its importance.  Secondly, most “suggest” questions aren’t totally novel questions, they are just contextual. Meaning we can look at the question and derive the answer from the information provided.  In this article, I wish to highlight some ways to think about how to approach such questions. Please refer to the 2018 paper when reading through this document, it will give you some context. Some simple general questions What is the difference between A & B? Is this linked to the earlier parts of the qn? What is the direction/flow of the qn? Why ...
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Dilution Effects on pH changes - Buffer For avoidance of doubts, in this post, we are referring to acidic buffer. In Acid-base Equilibria, there is a portion of the syllabus on buffers. Normal questions will ask for an outline of how the buffer works. They might ask you what is the mass of strong acid or base to a weak acid/base to add to create a buffer at a certain pH. A more advanced question will ask you what effects will dilution have on the pH. Generally, dilution has NO effect on the pH. Why is this so? If you look at the buffer formula, pH = pKa + lg [salt]/[acid], dilution does not affect the [salt]/[acid] ratio. i.e. they ...
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Nitrogen Compound Concept Map This is the final installation of organic concept maps. Feel free to print it out for your personal use. Please do not distribute. Back to Home of Best Chemistry Tuition ...
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Carboxylic Acid Concept Map This is the 8th installation of organic concept map. Please feel free to print it out for your personal use. Please do not distribute. Back to Home of Best Chemistry Tuition ...
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