The Chemistry Paper 2 is a paper that consists of short-answer questions and extended-response questions. This paper makes up of 40% (SL) or 36% (HL) of your overall chemistry grade. The maximum marks that you can receive is 50 for SL and 95 for HL and you will have 1 hour and 15 mins (SL) or 2 hours and 15 mins (HL) to complete. That means that you should only spent about 1 minute and 30 seconds per mark. So, read the tips below to brush up your exam skills so that you can save time!
1. Show Your Working and Don’t Forget the Units
Always show your working as it can get you points even if your final answer is incorrect. Your workings show your understanding towards the topic and it can also help you track through your steps when you realise that there is something wrong with your final answer. Also, don’t forget the units as they usually make up for your final mark of the entire response!
2. Round the Answers to the Correct Number of Significant Figures
Chemistry paper 2 includes a lot of calculations and there are two rules for rounding your answers.
- When the question clearly states that the answer must be given in a particular significant figure, follow the instructions.
- Generally, when nothing is mentioned in the question, round your answer to 3 significant figures. However, if there are other numerical values in the question, the significant figure in your answer should be the same as the least significant figure used in the question.
3. Read the Questions Properly to Identify the Key Terms
The questions will always include key terms that can help you identify which topic the question is from. It also tells you what kind of answer it is seeking for. On the other hand, using the keywords in your responses can also help you score points during the exam. Therefore, understand which words are from which topics to help you come up with a response that doesn’t go off the track.
Here are some examples:
| Question | Topic |
| Explain why the relative atomic mass of … | Atomic Structure: 2 |
| Describe the bonding between… | Bonding: 4 |
| Explain how a catalyst… | Kinetics: 6 |
| Describe the mechanism for… | Organic: 10 |
The following examples are the key terms that you should be using in your answers:
| Keywords | Topic |
| Delocalised electrons | Bonding: 4 |
| Activation energy | Kinetics: 6 |
| Exothermic/ Endothermic | Equilibrium: 7 |
| Functional group | Organic: 10 |
4. Familiarise Yourself With the Data Booklet
The most important tool for paper 2 is probably your data booklet. The entire booklet contains around 40 pages so make sure you know where everything is. The periodic table is crucial for you to know the specifics for each element. However, you should also know where you can find things such as the ionisation energies, bond enthalpies, standard electrode potentials, and strengths of organic acids and bases etc.. Knowing the data booklet inside out will save you so much time so familiarise yourself with it when you are practicing the questions from past papers!
5. Check the Number of Marks for Each Question
The number of marks indicates the number points that you should be making. If the question is a 3 mark question, it means that there should be at least three bullet points or sentences that answer the question. If you are not sure whether one of the points are relevant, then write everything in your head down so that you won’t be missing any points. Writing less might cause you to loose points but writing more can never be a disadvantage!
Here is an example:
| Question: Explain why [Cu(H2O)6]2+ is coloured. (4) |
| Answer: The compound contains partially filled d-orbitals that are split into two sets of different energy levels. When energy is absorbed, electron transmission occurs between the d-orbitals. This causes the complementary colour of the colour absorbed to be seen. |
Since the question is a 4 mark question, we will have include four keywords/ points (highlighted in bold) in our answer in order to answer it fully.
6. Skip Questions Whenever You Are Stuck
There are a lot of calculations and written responses in this paper. The paper itself contains a variety of topics scattered throughout the entire exam so don’t be scared when you are stuck. Move on to the next question to see if anything rings your bell and go through the exam paper until you reach the end. Once you finished going through the first round, return back to the questions that you were stuck on and go through the same process. If you are still stuck, flip through the data booklet to seek for hints. Most importantly, remember to relax and don’t panic!