Have you chosen Chemistry as part of your IB Diploma Programme? Congratulations, it is one of the most fascinating subjects out there. At the same time as being incredibly interested, it is also difficult. This means, your academic journey won’t be a walk in the park. Even if you study hard and diligently you are not immune to mistakes in IB Chemistry exam.
What are these mistakes, and most importantly, how to avoid them? Read further to learn how not to lose valuable marks.
Key Student Mistakes in IB Chemistry Examinations
We talked with TutorsPlus teachers and examiners to identify mistakes IB students make when preparing for and sitting their IB Chemistry exams. Below we’ll share their knowledge and discuss the most common ones.
No Explanation of Working Formulas for Chemical Reactions
Let’s start with one of the most common mistakes in IB Chemistry you should try to avoid – failing to provide clear explanations of the working formulas for chemical reactions. Since Chemistry is an experimental science, it’s critical to show your understanding of the processes involved.
Explaining the workings of chemical reactions is proof that you not only know the formulas but also the underlying principles. What’s even more important, detailed explanations of chemical reactions allow you to meet marking criteria and maximise your score. You simply cannot miss out on these valuable points because you don’t know the basics or lack time.
To ensure you know the formulas and can accurately write them, tape the periodic table to your note book, bathroom mirror or computer. Naturally, chemical elements and their symbols are something that you must know before you go to your final IB Chemistry exam.
Second, you should try and look for patterns and rules within chemical formulas. Of course, you can simply memorise formulas – you will have two academic years to do that – but if you recognise common patterns, it will be much easier to learn the chemical reactions.
Incorrect Spelling of Units of Measurement and Significant Figures IB Chemistry Study
It goes without saying that your answer must feature correct measurements. This means that there should be appropriate units alongside significant figures. Neglecting either will cause deductions in your marks.
Units define the nature of a measurement. An answer that has the right units is more precise than one without units. For example, ‘5 grams’ is a meaningful measurement, while ‘5’ alone lacks context, and can be meaningless.
But it is not enough just to specify a unit, you must also spell it correctly –5 g is a correct spelling while 5 gr, Gr, grm, and so on is not.
Last but not least, you need to make sure that all units within a calculation are consistent. Mixing units can lead to
Mixing units can lead to mistakes in IB Chemistry preparation and incorrect results.
When it comes to significant figures, their role is to indicate the precision of a measurement. It’s important that your answers have the correct number of significant figures based on the data you’ve received. The result of your calculations should have the same number of significant figures as the least precise measurement used in the calculation.
Common Mistakes in IB Chemistry: Drawing and Labeling Diagrams
Scientific drawings are an essential part of your IB Chemistry exams. Unfortunately, students tend to make errors when drawing diagrams, charts, or graphs.
Your task is to ensure your diagrams are well-organised, easy to read, and clearly labelled. Therefore, you need to avoid clutter and excessive lines.
Also, pay attention to detail. For example, when representing bond angles, you should show appropriate arrows for dipoles and accurately depict the number of bonds in chemical structures. Then, you need to use clear and concise labels for all components of your diagram. Avoid abbreviations that might not be universally understood.
It is also necessary to double-check the direction of arrows in chemical equations. An arrow pointing in the wrong direction will impact the accuracy of your representation, and this will cost you valuable marks.
As you prepare for your IB Chemistry exam, practice drawing various types of diagrams. This exercise will allow you to improve your accuracy and speed. We recommend using a pencil since it will let you make corrections and adjustments without erasing the entire diagram. To emphasise important components of your diagram, you can highlight or shade them.
Errors in IUPAC Nomenclature of Organic Compounds
As you know, IUPAC nomenclature is a systematic method for naming organic compounds. It consists of three primary components: the word root, primary suffix, and prefix. While it might seem complex, without understanding and applying these components correctly is impossible to succeed in IB Chemistry.
For starters, you need to be able to identify the functional group present in the organic compound to determine the correct suffix. For example, alcohols use the “-ol” suffix (such as methanol), while aldehydes use the “-al” suffix (such as methanal).
In terms of identifying the alkyl group attached to the parent chain, you may need to count carbon atoms to use the appropriate prefix.
Consistent practice is key to mastering IUPAC nomenclature. You need to know IUPAC nomenclature like the back of your hand. When you have a clear idea of word roots, suffixes, and prefixes, practice naming various organic compounds. Along with it, you can break down organic compounds into their individual components and apply the rules of IUPAC nomenclature.
It might also be useful to create flashcards to easier memorise common functional groups and their corresponding suffixes.
Incorrect Chemical Equations and Stoichiometry
Chemical equations are the symbolic representations of chemical reactions. They depict reactants, products, their ratios, and states.
Before you submit your IB Chemistry exam paper, you need to double-check the chemical formulas of reactants and products. Don’t forget to include the states of matter (solid, liquid, gas, aqueous) for each substance in the equation.
Another common mistake in IB Chemistry is incorrect balancing. If the number of atoms of each element is not equal on both sides, it is a sign that your formula is not right. Make sure you consider stoichiometric relationships before you hand in your work.
To avoid stoichiometry mistakes, you must have a clear understanding of the concepts of atoms, molecules, and moles, as well as be able to determine the mole ratios between reactants and products. Again, consistent practice to solve stoichiometry problems can reinforce your understanding.
Mixing Up Organic Functional Groups
We have already pointed out the importance of learning IUPAC Nomenclature. If you know it, it shouldn’t be that hard to specify the right functional groups. But if it is not your strength, it is easy to mess up amines with amides, esters with ethers, or alcohols with aldehydes.
It goes without saying that you need to have a foundational understanding of the key organic groups. This includes, for instance, characteristic reactions within each group (such as nucleophilic addition, substitution, and elimination), the types of bonds, and their structures. Get a solid grasp of these, and there won’t be any confusion during your IB Chemistry exam.
Mistakes in IB Chemistry: Errors with Oxidation States
To understand redox reactions, you need to be well-versed in oxidation states, which measure the degree of oxidation or reduction of an atom in a molecule or ion. Mistakes in determining oxidation states can lead to errors in balancing equations and analysing chemical processes.
It all starts with grasping key concepts such as Oxidation (the loss of electrons), Reduction (the gain of electrons), and Redox Reactions (chemical reactions involving both oxidation and reduction).
Next, you need to avoid confusing cations with anions – the former have positive oxidation states, while the latter – negative oxidation states.
Then, it is crucial to be able to correctly identify the direction of electron transfer in half-reactions. Remember, electrons flow from the reducing agent (gets oxidised) to the oxidising agent (gets reduced).
In addition, you should pay close attention to the oxidation states of ligands, especially complex ions. Ligands often have specific oxidation states that contribute to the overall charge of the complex.
There is plenty of room to make a mistake with oxidation states. However, a systematic approach can help you avoid errors. Start by assigning oxidation states to known elements (e.g., alkali metals are always +1). Then, use the overall charge of the compound to determine the oxidation states of other elements.
Numerical Errors and Miscalculations
Nobody is immune to numerical errors and miscalculations, even if you know all the important chemistry concepts and reactions. This means that double-checking your calculations is an absolute must.
After completing your calculations, take a few minutes to review your work and try to find possible errors in arithmetic or unit conversions. If the numbers you received seem right, compare them with the number of significant figures based on the given data. Remember, significant figures must be consistent throughout your calculations.
At the end, look at units again. Did you make sure to apply conversion factors and cancel out units in the right way?
General Tips to Avoid Common Mistakes in IB Chemistry
Now that you know which mistakes tend to slip into students’ answers, let us provide a few valuable tips on how to avoid them.
Analyse the Question and Problem in Detail
Sometimes, students don’t fully understand exam questions. As a result, they provide an irrelevant answer, which brings fewer points if any. Although it is a common IB Chemistry mistake, it is avoidable if you read the question carefully.
Start by identifying and underlining key terms, including command terms, and concepts in the question. This simple action will help you focus on the exact things the question requires.
If you need to solve a problem, it’s worth breaking it down into smaller, more manageable steps. After solving them one after another, you can easily provide a solution to the problem you have at hand.
It is also beneficial to visualise the chemical process or experimental setup described in the question. This can provide a clearer picture of the context and help you interpret the given information.
Once you know what the question asks you to do, consider how it relates to the concepts and topics you’ve studied in the course.
Focus on Structures and Properties
To succeed in IB Chemistry, you need first to make sense of its fundamentals such as molecular structures, compositions, arrangements, and physical attributes. Therefore, you should dedicate a good portion of your revision time to solidifying your knowledge and bridging the gaps in these areas.
For example, you must be able to apply the VSEPR (Valence Shell Electron Pair Repulsion) theory to predict molecular geometry based on the arrangement of electron pairs around the central atom. If you know how the VSEPR theory works, you can easily determine bond angles and molecular polarity, as well as predict properties such as solubility and reactivity.
Along with it, it is paramount to know the different types of intermolecular forces (London dispersion forces, dipole-dipole forces, hydrogen bonding) and their relative strengths. Similar to VSEPR theory, intermolecular forces influence physical properties. You can have a better idea of boiling points, melting points, solubility, etc. if you focus your practice on this area of Chemistry.
As we have already said, many IB Chemistry exam questions will revolve around functional groups. It is impossible to succeed if you don’t know the properties of alcohols, aldehydes, ketones, carboxylic acids, etc. Make sure you walk into the exam room with a clear idea of how functional groups influence the reactivity of organic molecules as well as the ability to predict the products of chemical reactions.
Use Samples of Past Work to Correct Mistakes in IB Chemistry
One of the best things when it comes to preparation for any IBDP exam (and Chemistry is no exception) is that you can rely on the experience of students before you. In other words, the International Baccalaureate makes past exam papers available for current students. Of course, the exact questions and problems will be different in your exam, but they will give you a good idea of what to expect. Specifically, you can learn an exam format, question types, how much marks they are worth, and more.
We recommend spending as much revision time as possible to practice with past papers. Why? Well, this can help you:
- Identify recurring themes and concepts. This way, you can benefit from a focused revision;
- Develop effective strategies for answering questions, managing your time, and avoiding common mistakes in IB Chemistry;
- Boost your confidence in your ability to answer IB Chemistry exam questions;
- See the errors you are prone to, so you can select strategies to avoid them.
The more you practice with past IB exam papers, the better you’ll be equipped to pull off various question types. Ideally, you should limit your time to the allotted exam duration to create a realistic exam environment.
After completing a past paper, carefully review your answers and compare them to the marking scheme. If you weren’t perfect in your answers and made mistakes, don’t get upset. On the contrary, use these mistakes as an opportunity to identify your weak areas and improve them before D-Day.
Do you feel you require help with IB Chemistry revision? Don’t be afraid to ask for it! Your teacher or a TutorsPlus Chemistry tutor can provide the guidance and support you need.
Keep Track of Time Using Past IB Exam Papers
You will have plenty of time to prepare for your IB Chemistry exam. It doesn’t, however, mean that time is your friend. On the contrary, time works against you. If you don’t learn how to manage it, your chances of success are going to approach zero.
But how to make friends with time?
First of all, it would help if you created a study schedule. Start by dividing the IB Chemistry syllabus into smaller, manageable sections and allocate time for each one based on their difficulty and importance. Be prepared to adjust your schedule to accommodate unexpected challenges or changes in your understanding.
There are likely topics where you feel less confident or have struggled in class. Make sure to give more time to go over the areas that require attention.
As we have already mentioned, it is important to practice with past IB exam papers under time conditions. This exercise will help you understand whether you are able to tackle the exam within 3 (for SL) or 4.5 hours (for HL).
When sitting the actual exam, time management is important as well. Here are some tips to help use your limited time wisely:
- Before you begin answering, quickly scan the entire paper to get an overview of the questions and their point values;
- Start with questions you feel confident about to build momentum and gain confidence;
- Allocate time for each section of the exam based on its point value. Avoid spending too much time on any one question, especially the ones with low marks;
- Leave some time at the end of the exam to review your answers and check for careless mistakes.
Check Your Answers to Prevent Errors in the IB Chemistry Exam
Speaking of mistakes in IB Chemistry preparation, they can crawl into the works of even the brightest students. If you don’t want silly mistakes to take valuable marks from you, this is what you should do:
- Ensure that all your answers include the correct units of measurement;
- Your answers must feature an appropriate number of significant figures based on the data you’ve received;
- Double-check any complex calculations to avoid numerical errors;
- Make sure all chemical equations are balanced, i.e. they have the same number of atoms of each element on both sides;
- Review the formulas and stoichiometric relationships for correctness;
- Take a closer look at your explanations. Are they clear and directly address the question? Are they supported by relevant evidence such as theoretical concepts?
Conclusion
You should study hard to understand tricky Chemistry concepts and solve intricate problems. But even if you’re confident in your knowledge, it doesn’t mean that a 100% result is guaranteed.
Sometimes unfortunate errors such as wrong units of measurement or inaccurate significant figures can impact your gain. However, if you’re aware of the most common mistakes in IB Chemistry exam and know how to effectively avoid them, you have a greater chance to reach the score you hope for.
You give IB Chemistry revision all your effort but still lack confidence? Are there questions that make you nervous? Then it’s high time to take your revision to a whole new level.
TutorsPlus is a team of experienced IB tutors, teachers, and examiners, who have led thousands of students to succeed. With our help, not a single chemistry concept will remain unclear. We offer targeted IB Chemistry exam guidance as well, from assessing your knowledge and areas of improvement to providing valuable strategies to nail your assessment.
We are happy to assist you in every way that we can. Feel free to contact us at 022 731 8148 or info@tutorsplus.com if you have any questions or would like to hire one of our knowledgeable tutors.
By Sara Lloyd
Sara has been an education consultant for TutorsPlus for 15 years, and is an expert on international IB education. She is also a parent of two lively children.
