What to do if you only have 2 months left before A levels H2 Chemistry Exam

January 3, 2014 A Level Chemistry Study Technique 0

Mr John Soh shares his plan on how a student can try to improve his A Levels Chemistry grades from U to A within 2 months.

 

2 month plan to substantially improve a student?s Chemistry level

Preliminaries:

The student should realize that he is in an extremely disadvantaged position if he wishes to improve his Chemistry grade from U to A/B in 2 months. Expert help is strongly recommended, because the odds are stacked against him for the following reasons:

  1. The material in A Level Chemistry is more challenging than that in O Level Chemistry, with higher order thinking skills required for many topics.
  2. The difficulty of the final exam has been increasing in recent years, with an increasing focus on application-based questions.
  3. The competition is fierce, with a significant portion of the competitors being top O Level students/IP students.

However, if the student wishes to take on the challenge individually, the following approach would be a plausible strategy to obtain the greatest improvement in his Chemistry grade.

First, understand that A Level Chemistry contains 3 major sections: Physical Chemistry, Organic Chemistry and Inorganic Chemistry. The approximate weightages are 42%, 42% and 16% of the theory paper respectively.

Also, recognize the nature of each section. Physical Chemistry contains 5 core topics ? Chemical Bonding, Energetics/Chemical Thermodynamics, Equilibria (Chemical and Ionic), Kinetics and Electrochemistry. Even though some material in a core topic is related to the other core topics, a large portion of material is unique to that particular topic. Thus, it is possible to study these topics separately. Each topic contains several core ideas and key concepts, and the emphasis is largely on the application of these.

As for Organic Chemistry, all of the topics, with the exception of protein chemistry (part of nitrogen compounds), are interrelated as functional groups can be converted to each other through chemical reactions. Even though the section is broken down into individual topics for the ease of study, the student will need to integrate the topics ultimately. For this section, emphasis is on both the theory and the understanding and application of the theory. This is the most demanding section in A Level Chemistry.

For Inorganic Chemistry, a major theme is the use of Atomic Structure and Chemical Bonding key concepts such as effective nuclear charge (Atomic Structure) and structure and bonding (Chemical Bonding) to explain chemical properties. Questions involving the section tend to be memory-based, and the student is likely to do well if he manages to remember all the key concepts.

Lastly, the student should be aware that key concepts can be tested at 3 levels in the final exam: Knowledge, Understanding and Application. The most basic level is the Knowledge level, which generally examines the student on his ability to recall the key concept. The next level, the Understanding level, tests the student on whether he understands the chemical principles behind the key concept. The final and hardest level, the Application Level, requires the student to use his knowledge and understanding and apply them to situations typically not familiar to him. In recent years, the questions in the final exam have been increasingly Application-based.

Strategy:

First 4 weeks ? Sharpening the saw

In light of the above, the student is advised to focus on Organic Chemistry first. Organic Chemistry can be divided into 3 large portions: Reactions, Mechanism and Theory. The student should ensure that he is able to recall the reagents and conditions for all the Organic Chemistry Reactions, and also understand the main chemical principles involved in each of them.

For instance, the student should be able to recall that excess ammonia with heating in a sealed tube is used to convert a haloalkane to a primary amine. Excess ammonia is required to prevent polyalkylation, since the primary amine product can also act as a nucleophile and react further with the haloalkane, forming higher order amines.

For the mechanism portion, the student should be able to describe all the important Organic Chemistry Mechanisms, and also understand the key characteristics at play in each mechanism. An illustrative example would be the free radical substitution mechanism of alkanes ? the student should be able to describe the initiation, propagation and termination steps with the aid of chemical equations, and also recognize that the free radical substitution reaction is a random process as well as a chain reaction.

As for the theory portion, the student should have a strong understanding of the two fundamental phenomena taking place in organic molecules ? the inductive effect and the resonance effect. He should then practice their application in the exploration of the core Organic Chemistry theory questions: the acidity of the hydroxyl compounds, the basicity of the nitrogen compounds and the ease of hydrolysis of the halogen compounds.

It will be better to defer the coverage of the Protein Chemistry chapter to a later date, since this chapter requires an integration of various topics in Chemistry including Organic Chemistry, Equilibria, Electrochemistry and Chemical Bonding.

Because of the lack of time, he should also aim to cover the 5 core Physical Chemistry topics concurrently. Focus on the major key principles behind each topic (they tend to be few in number), and keep practicing questions to deepen the understanding of each principle. For instance, the Energetics topic in Physical Chemistry generally involves energy balance questions and energy cycle problems. The student should understand the key principle behind the energy balance (the conservation of energy principle) and energy cycle (Hess Law), and deepen his understanding by practicing as many questions as possible. With Physical Chemistry and Organic Chemistry covered, questions which the student should be able to attempt in the final exam would constitute at least 70% of the marks.

 

After the first month ? Review and Reflection

Go to www.seab.gov.sg and download the A level syllabus. All the key concepts that the student is required to know is found under the learning objectives section in each chapter. At this moment, the student should read through every key concept in the core Physical Chemistry and Organic Chemistry chapters, and ensure that he has met all of them. If he feels that he has not, there is still time to refresh and revise!

5th to 6th week ? Practice and Inorganic Chemistry

The student can now practice exam papers to put his knowledge and understanding to the test. He probably would still not be able to answer Inorganic Chemistry questions, but he can leave them aside for now. Physical and Organic Chemistry questions should be relatively easier.

Now would also be the time to start remembering all the Inorganic Chemistry material. Once the student is done, he should check against the key concepts for the Inorganic Chemistry section to ensure that he has met all the examinable criteria.

 

7th to 8th week ? Practice, Practice, Practice!

In the final lap of the journey, the student needs to practice as many past year exam papers as possible, due to the increasing difficulty level of the final exam. Preferably, he would be able to complete the A level papers spanning the past 3 years (at least), and also 3-4 school prelim papers if he has the time.