Prior to the IB, I had always been struggling with Chemistry. However, through my IB experience, HL Chemistry became a subject that I enjoyed and did well in. I hope to share some pointers about how you can boost your marks in both paper 1 and 2, but my key focus will be on paper 2, where students tend to have more difficulties.
(First examination May 2016):
|Paper||Time||Score out of||Weightage|
|2||2 hr 15 min||95||36%|
Do note that depending on whether examinations are cancelled due to the pandemic or papers are being removed, the weightage will differ for different examination sessions.
Identifying the topic:
Recently, the past few HL Chemistry paper 2 papers only consisted of about 7 to 8 questions. However, over the course of the 2 years, you would have learnt about 11 chapters thus this means that 1 question would probably test you on content from more than 1 chapter. The paper will cover most if not all of the chapters albeit some having more weightage than others (such as organic chemistry).
For each part of a question (e.g. question 1.a.i), you need to first identify what topic the question is asking you about. This will allow you to think about everything that you have learnt from that chapter and phrase your answer in the correct manner. If you are unable to identify the topic or identify it wrongly, it will be very difficult for you to write down anything and it will be difficult for the marker to give you any marks.
Sometimes, the topic being tested is very obvious, however, there may be times when this is not the case. For such questions, you should use the phrasing of the question to give you hints. During one of my examinations, I was very confused with what the question was asking as the previous parts were all relating to equilibrium (chapter 7). I had trouble trying to come up with an answer till I finally realised that it was actually relating to kinetics (chapter 6). When I was able to identify the topic, I was able to answer the question because I was following the right train of thought. From the past papers that I have done, these are 2 topics that are commonly tested together.
|Explain how increasing… affects time taken…||Kinetics||6|
|Explain how increasing… affects yield||equilibrium||7|
|Explain bond length…||Bonding||4|
|Explain the mechanism for the reaction||Organic chemistry||10|
|Use a Born-Haber cycle to…||Energetics||5|
This list is not at all exhaustive however, as you do more papers you will realise that certain keywords will only refer to certain topics and this will ensure that when you answer the question, the scope that you are even considering is in the right general direction.
Using key terms:
Most of the IB mark schemes are very basic, with most of the answers written in point form. However, for similar questions, certain keywords will constantly appear in the mark schemes. These words are generally chemistry-related words that you would have already learnt in class so just remember to add them in your answer! Markers are looking out for these words and once they see it used appropriately in your answer you will be given the marks. For an explanation question, you should not answer in point form but rather revolve your answer around these keywords, using them as the points you are trying to make.
Below I have added another non-exhaustive list just to give you an idea of some of the keywords for HL Chemistry. You can even compile your own list and use it as revision by going through what they mean or when they are used.
|Delocalised electrons/ resonance structure||Bonding||4|
|Initiation, propagation, termination (for free radical substitution)||Organic Chemistry||10|
|Chiral carbon||Organic Chemistry||10|
Avoid careless mistakes
Once you have finished your paper, hopefully you will have time to go back and look through all your answers.
Firstly, ensure that for all calculation questions, you have rounded off all answers to the correct number of decimal places (addition, subtraction and average) or significant figures (multiplication and division).
Secondly, remember to include all the necessary units, being mindful of the requirements of the question eg. Jmol-1 or kJmol-1. (this is very common when doing questions involving using entropy and enthalpy to calculate gibbs free energy – energetics chapter 5).
Know your data booklet
The data booklet is a 40 page booklet that will be given to you to use during paper 2 for HL Chemistry. Although for most questions, the question will tell you to go to certain tables in the booklet to find the relevant information, it is best if you already know where you can find everything.
Knowing what kind of information is in the data booklet and where you can find them will not only save you time during the examinations scrambling to flip the pages, but also reduce the number of things you need to memorise as you can easily find them during the examination.
I would recommend printing out a hardcopy if you are able to do so. This will allow you to use it as you learn new topics such that you can keep tabs on which pages are meant for which topics. While doing practice papers, make full use of the data booklet so that during the examination, you will not feel so lost.
Paper 1 consists of 40 multiple-choice questions and most of them are generally doable. Apart from 2 or 3 questions that might be tricky or more difficult, you should still aim to score well and get the rest of them correct. If you are familiar with the content, getting a score of 34 or above would put you in a very good position to get a grade 6 or even grade 7.
Be mindful of mental calculations as you do not have access to a calculator. During practices, get comfortable calculating with decimal places and working with log for simple pH calculations. In addition, it is important to remember that you will only have access to the periodic table and not the entire data booklet. This means that there may be things you will still need to know without the help of the data booklet, at least for this paper.
When it comes to HL Chemistry papers, you want to be exam-smart in order to maximise your marks. Knowing the resources available to you, how questions are phrased and how some topics are tested will give you an edge in completing the paper quickly and accurately. I hope that these tips I have given to you will allow you to ace your paper and help you achieve your desired scores.