This book contains 50 lies taught in the VCE Chemistry course.
These lies include well-meaning simplifications of the truth, mistakes in the textbook, and, in a few extreme cases, blatant falsehoods.
This book isn’t a criticism of the VCE Chemistry course at all. In fact, I just want to highlight the sheer complexity of Chemistry and the need to make sweeping generalisations at every level so it can be comprehensible to our students. This is a legitimate practice called constructivism in pedagogical circles. (Look that up.)
Many of these ‘lies’ taught at VCE level will be debunked by your first-year chemistry lecturers at university.
Here’s a preview of some of the lies mentioned in the book. Check out all 50 by clicking the download link at the bottom of the page.
Click to download REDOX RULES posters for VCE Chemistry
What’s redox? We never learned that!
Yes, you did. I use the term “redox” to refer to all of the following chapters in Heinemann Chemistry 2, which you will have learned at the end of Term 3 (September).
Chapter 26: Redox (revision of Year 11)
Chapter 27: Galvanic Cells
Chapter 28: Electrolytic Cells
Don’t underestimate redox
The VCAA has consistently used redox to discriminate which schools and students have the self-discipline required to keep studying at the end of the year. Studies show that redox is taught at a time when student motivation is at its minimum: energy levels are low, emotions are high, and graduation is just over the horizon. Many schools and students gloss over these topics because they’re running out of time, any many students think they’ve grasped the topic – when they’ve actually grasped misconceptions instead.
Here are some popular redox lies (misconceptions)
LIE #1: The polarities switch during recharge Nope. The polarities never switch. It’s the labels of ‘anode’ and ‘cathode’ that switch because the electrons are flowing the other way through the external circuit. Polarity is permanent.
LIE #2: Hydrogen fuel cells don’t emit any greenhouse gases Wrong. They emit H2O, which is a powerful greenhouse gas. If you don’t believe that the VCAA can be this pedantic, think again. Read their 2015 Examiners Report here.
LIE #3: Each mole of electrons forms 1 mol Ag, 2 mol Cu or 3 mol Al in a cell Wrong again. If you look at the half-equations, you’ll see that each mole of electrons actually forms 1 mol Ag, 1⁄2 mol Cu or 1⁄3 mol Al. That’s why I teach “1, 1⁄2 and 1⁄3 moles” instead of the typical “1, 2, 3 moles” rule.
LIE #4: Temperature increases the rate of reaction in electroplating
Wrong! Remember that Faraday’s first law states that m ∝ Q. Because Q = I×t, only those two things – current and time – can affect the mass deposited at the cathode.
LIE #5: Electrons always leave the anode and go towards the cathode Wrong again. Electrons go RACO: to see what that means, download the posters above. This question appears in recent versions of Chemistry Checkpoints. Give it a try.
LIE #6: The cathode is always positive Ask your teacher.
LIE #7: Ions flow one way in the salt bridge
Nope. Anions always migrate to the anode; and cations always migrate to the cathode.
LIE #8: KOHES always works for balancing half-equations
KOHES only works for cells with acidic electrolytes. For cells with alkaline electrolytes, which sometimes appear in VCAA papers despite not being in the study design (see page 46 here), you’ll need to use KOHES(OH). Here’s KOHES(OH) explained:
Do KOHES as normal
Add the same number of OH–(aq) ions to each side of the half-equation to balance out the H+(aq)
Cancel and simplify. Remember that H+(aq) + OH–(aq) makes H2O(l). Remember also to cancel out any remaining H2O(l).
LIE #9: I can balance an unbalanced redox equation by putting numbers in the equation Don’t be fooled by this one! The ONLY way to balance an unbalanced redox equation successfully is to do the following:
Separate it into two half equations
Balance them using KOHES or KOHES(OH) as appropriate
Multiply them and recombine
Cancel and simplify
That’s a lot of work but it’s the only way to do it successfully. If you try to ‘cheat’ by just writing numbers (molar coefficients) in front of the reactants and products, you’ll find that the charges don’t add up, and you’ll get zero marks for the question.
LIE #10: I can break up polyatomic ions to make balancing half-equations easier
Nope! You’re only allowed to separate aqueous species in a half equation or an ionic equation. Because the Mn and O are actually bonded together in a polyatomic ion, you’ll need to write this:
If in doubt, keep it intact and it’ll cancel out by the end if it’s a spectator ion.
LIE #11: The two reactants that are closest together on the electrochemical series react Not always true. Use SOC SRA instead, which is explained in the posters above. Still struggling? Ask your teacher or tutor for help.
LIE #12: Oxidants are all on the top of the electrochemical series They’re actually on the left, and all the reductants can be found on the right side of each half equation in the electrochemical series. There is no top/bottom divide on the electrochemical series: only a left/right divide of oxidants/reductants.
Decorate your school/bedroom/hallway
Surround yourselves with truthful redox revision using these 17 free Redox posters. I’ve had these up around the whiteboard for a few weeks now – they’re a constant reminder to students that redox has many ideas that are always true.
One more tip: print and laminate an electrochemical series (available here) so you can annotate it during dozens of practice dozens without wasting paper. Good luck!
The groups credited for creating them – in Japan, Russia and the US – have spent several years gathering enough evidence to convince experts from Iupac and its physics equivalent, the International Union of Pure and Applied Physics, of the elements’ existence. All four are highly unstable superheavy metals that exist for only a fraction of a second. They are made by bombarding heavy metal targets with beams of ions, and can usually only be detected by measuring the radiation and other nuclides produced as they decay.
Only positively-charged fragments from mass spectrometers produce a peak on the spectrum. Uncharged free radical fragments are not detected because they lack a positive charge.
Weak acids with a lower Ka value are the weakest… this means that they ionise to a lesser extent when in aqueous solution, giving rise to a lower concentration of available H3O+(aq) and a higher pH.
The conversion of triglycerides (a type of ester) into biodiesel (another type of ester) is called transesterification.
The covalent bonds between deoxyribose and phosphate groups in DNA form a group of atoms called a phosphodiester group.
Ether bonds and glycosidc bonds are not the same. Ether bonds are C-O-C. Glycosidic bonds are a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate.
Amide groups and peptide groups are not the same, either. Amide groups are CONH. Peptide groups are CONH between amino acid residues in a polypeptide chain. Nylon, for example, has amide groups (CONH) which aren’t called peptide groups.
Ether: C-O-C Ester: COO Amine: NH2 Amide: CONH
The molar mass of any amino acid without its Z-group is 74 gmol-1.
The molar mass of glucose, fructose and galactose (all monosaccharides) is 180 gmol-1. By coincidence, aspirin is also 180 gmol-1.
The molar mass of sucrose is 342 gmol-1 because (180*2)-18=342.
In general, energy is required to break bonds. Energy is released when bonds are formed.
Use the formula C-(H/2) to find how many C=C are present in a fatty acid (only works for fatty acids).
Use the shortcut formula (Ka/[acid])^0.5 to find % ionisation of a weak acid.
Use -log(Ka) to find the exact pH at the end point of an indicator.
Use the quick titration formula for rapid multi-choice titration questions: c1v1/ratio1 = c2v2/ratio2
A hydrogen bond is an intermolecular bond that forms between O-H groups. The covalent bond between the O and the H is not a hydrogen bond.
Can you write the half-equation for the reaction occurring at the anode in an ethanol-oxygen fuel cell with an alkaline electrolyte? Tip: start by writing the known reactants and products then use KOHES(OH) to balance your equation.
The products of a titration determine the pH at the equivalence point. For example, the the pH at the equivalence point in a titration between CH3COOH(aq) and NaOH(aq) is around 8.5 because at equivalence point, only products are present: Na+(aq) and CH3COO–(aq). The ethanoate ion (CH3COO–(aq)) is a weak base, which makes the solution produced slightly basic.
If you have absolutely no clue in the multiple choice sections, pick C. In the last 4 years of VCE Chemistry examinations, C has been correct 50% more of the time than B.
The multiple choice questions really do get harder towards the end. I’ve done the statistics.
Use your reading time wisely. During reading time, read all the questions with the following idea in mind: “how would I do this question?” without actually doing the question.
Bring sharp pencils.
Sleep early tonight (before 9pm). At this stage, getting enough sleep is far more important than revising those tiny details that may or may not come up in the examination.
Inspired by the formula booklets used by VCE Physics and VCE Maths Methods, here’s an 8-page Chemistry formula booklet you can use for your Year 11 and 12 Chemistry assignments. This custom-made booklet is a a collection of reliable formulae that I have been using to answer VCE Chemistry questions while teaching and tutoring.
There are 76 formulae in total, at least 10 of which are original. Orders are shipped on A3 paper, stapled along the spine and folded to an A4-sized booklet that resembles the VCAA Data Booklet.
Orders from schools, students and tutors are all welcome. Price includes free international delivery and 10% voucher for the T-shirt store.
The VCE Chemistry examination is only 22 days away. As you complete at least one practice paper each dayand correct them ccording to your revision timetable, you’ll be finding that you’ve already mastered certain topics while others remain difficult.
Patterns emerge in student readiness: each year, electrolysis is the worst-studied topic on the course. Because VCAA has a reputation for asking questions on topics that students repeatedly got wrong in previous years; I decided to test this hypothesis by getting real data from recent examination reports and displaying it on a scatterplot of:
how difficult each topic is (% of marks lost) on the x-axis
how often the topic is asked (marks per paper) on the y-axis
The results were fascinating. While it’s impossible to say with any certainty which topics will be on the examination this year, previous years’ examination papers have placed more emphasis on the difficult topics (electrolysis, Ka, redox and biofuels). Focus your revision on these topics again this year.
Conclusion: Focus your Chemistry revision this week on your least favourite topics… those topics will probably be worth more marks in the examination!
Calorimetry can be a confusing topic. Avoid common errors by following these essential tips:
Always label the units of E (kJ or J) above the E. This is the most common source of error in calorimetry calculations. Try this quick way to remember the required units of E: If there’s ΔH in the equation, the units are kJ; otherwise, the units are J.
In E=mcΔT, all the variables refer to the mass of water being heated. A common error among students is to use the mass of limiting reactant instead of the mass of water. Generally, m in this equation is 100 g or a similar round number.
Never convert ΔT to kelvin. Temperature changes are the same in kelvin and celcius… never add 273 when finding ΔT.
No calibration step? Use m×c instead. Because E=mcΔT and E=CfΔT, it therefore follows that Cf ≡ m×c. For example, if we’re heating a 100.0 g of water without a Cf, we should use Cf = 100×4.18 = 418 J K-1 instead.
In ΔH = E/n, n denotes the number of moles of limiting reactant. Never add up the number of moles of reactants: use the number of moles of limiting reagent only.
Calculate twice. Students most often make mistakes when converting hours or days into seconds. Many answers are therefore wrong by a factor of 60. Do your calculations twice: once while doing the question and again when you check over your answers at the end of the SAC or examination.
Know a ballpark figure. Neutralisation and solubility reactions tend to have 2-digit ΔH values; combustion reactions tend to have a 3-digit ΔH and explosive reactions tend to have a 4-digit ΔH. If you get a 5-digit ΔH value, you’ve probably forgotten to convert your answer into kilojoules!
Remember the ‘+’ or ‘-‘ sign! The calculator doesn’t know whether the answer should be positive or negative. Think about it yourself instead: endothermic reactions need a ‘+’ sign and exothermic need a ‘-‘ sign. VCAA awards a whole mark for getting the ‘+’ or ‘-‘ sign correct! It’s possibly the easiest mark in the whole paper.
Consider getting a home tutor who can answer your questions and explain difficult concepts to you. Students learn much faster with a tutor than on their own.
Track your progress in VCE Chemistry with this A3 size progress tracker. Cross out or colour in each box as you complete it, and write your scores in . Start at the bottom (highlighted) and work your way upwards.
A ‘minimum expected level of examination preparation’ of 26 examination papers is labelled on the chart. Write your percentage scores in each of the boxes as you mark each paper. When you’re achieving past/practice examination scores concordantly above 90%, you’re ready to sit the VCE Chemistry examination.
1. Develop excellent study skills. Cultivate ideal study habits such as waking up early, reading your notes before school, doing all homework on time and studying even when there’s no homework set.
2. Stay committed and know what you want and WHY. People who know why they do what they do are far more likely to persist and put in the huge number of hours required to excel at that particular skill. All successful people were driven by a higher. Find your why and you’ll feel more motivated to study VCE.
3. Keep motivation levels high and consistent throughout the year. Remind yourself constantly why you’re studying the VCE subjcets you’ve chosen.
4. Do not “over-indulge” in VCE tutoring. Your tutors and teachers can only take you so far. The highest-achieving students are those who are self-motivated: they push themselves and study even when nobody asked them to. Become self-motivated and use your tutoring time wisely to maximise your performance in VCE exams.
2. There are two things you need to do: make great notes and do practice questions.
3. Build on your notes from external sources (other people’s notes and the textbook)
4. Mark your questions – or get them marked! Akhil says that while it’s an excellent learning exercise to practice marking questions by yourself, it’s also necessary to get your practice papers and Checkpoints questions marked by a teacher or tutor because they’ll be more vigilant with sticking to the marking scheme and can pick up slight errors in wording that are easy to miss if you mark your own work.
Memories and connections are some of the most valuable things you’ll take with you from Year 12. Keep in touch with as many people as possible both officially (using alumni networks) and unofficially (using social media). People move in different directions after graduation and you’ll be surprised at how your friendships evolve, too: classmates who were mere acquaintances during school might become very close friends in five years’ time. Keep in touch with all your classmates to make sure you don’t miss out on these future business connections, too. You might even meet again one day sitting opposite each other at a job interview!
Remember that your ATAR is only a means to a much more meaningful goal: it’s the key to a university course of your choice. Strive for an ATAR that’s high enough: there’s no need to stess yourself out by aiming for a ‘perfect’ score of 99.95. Your ATAR is like a disposable key: it gets you into university but doesn’t help you while you’re there. Nobody asked me what my A-level results were throughout my undergraduate years at Cambridge. High-school results simply weren’t important.
3) A Relentless Work Ethic
You’ve worked harder in Year 12 than you’ve ever worked in your life. If you want to be successful, you’ll have to maintain this level of hard work – or even increase it – to accomplish your goals in life. You’ve learned the difficult way that in Year 12, going to school and doing all the required homework isn’t enough. You’ve figured out in Year 12 that you have to spend hours reading the textbook by yourself, doing practice question sets that aren’t on the course, and making summary notes that your teacher will probably never see in order to get a high grade.
The relentless work ethic you’ve garnered will help you to conquer bigger obstacles in the years that follow. Give every major event in your life at least as much passion, dedication and preparation that you gave to your VCE examinations and you’ll be sufficiently prepared for the challenges that await you in the future. VCE is pre-season training for life.
Is there anything I’ve missed from this list? Is an ATAR more than just a “key to a university course”? Let us know in the comments section below.
You perform much better when you warm up before strenuous physical exercise. The same applies to Chemistry, too: if you warm up your brain before coming to class, you’ll feel more alert during the lesson and you’ll learn heaps more as a result. Here are some of the benefits of warming up before coming to class.
The best warm-up: read the textbook before class
One of the best warm-up drills is to read the relevant textbook section before going to class. Try to pre-read your textbook section no more than 24 hours before the lesson takes place; for example, during breakfast. Even though not all of the information made sense to me during this initial pre-read, it will at least make you understand the lectures a little better. Knowing key definitions before the lecture begins is crucial to understanding much more of what the lecturer is saying. You’ll also walk into the classroom with questions already in your head, ready to ask. This impresses the teacher and your classmates.
FOCUS during the lesson and make Cornell Noteswhile the teacher is talking. In addition to writing down key information the teacher tells you and writes on the board, write down any questions you might want to ask them later. Cornell Notes are an excellent way of doing this: you put your question in the Cue Column and leave the right part blank: you can fill this in with your answer at a later date (or by asking the teacher at the end of the lesson). Trying to formulate questions to pose to the teacher while you listen to a lesson is a good way of committing the information being learned to your long-term memory. This works because you’re invoking higher-order thought processes and learning more actively.
With this in mind, review your notes within 24 hours of the lesson and again at regular intervals afterwards. You’ll need to continually improve your notes after you’ve made them: answer questions you left blank in the Cue Column, insert definitions to confusing words, and label the diagrams you left blank during the lesson. Stay ahead of that forgetting curve!
Don’t have time to pre-read the textbook? Nonsense!
Skim-reading your textbook section over breakfast takes about 10 minutes, and reading and highlighting key definitions takes just another 2 minutes. By investing 12 minutes of time before class, you’ll learn more during the lesson and waste less time afterwards trying to decode what the teacher was saying. You’ll also have the confidence and the ability to answer to more questions in class. Your peers will start to see you as the person who always knows the answer to the teacher’s questions, which gives you a self-fulfilling reputation for being ‘smart’.
Reviewing and fleshing our your notes after class doesn’t take long, either. The exact time depends on the difficulty of the topic. Remember that the time you invest doing the above three things will pay off during the examination. If you don’t have time to do these three things, then make time. Get reading!
How do you warm up before class? What study habits help you the most? Share your ideas in the comments section below.
It’s that time of year when students are starting to plan their exam revision. Getting to grips and memorising all you have learn over the past year is only half the battle, as new research from productivity website Stop Procrastinating has found that 64% of students believe that exam stress and anxiety is affecting them so much that it will lower their performance and affect their grades.
The poll of 2000 undergraduates heading into their final exams found that 66% of students believe their stress levels are greater than in the past due to modern day problems, such as the difficult jobs market. They feel that a lower grade could affect the rest of their lives, closing doors to opportunities and causing them to miss out on jobs.
The survey found that procrastination was a major cause of stress. Students today have more opportunities for distraction with the rise of the Internet, smart phone and social media. A massive 45% of students surveyed said they wasted time on the Internet or social media instead of revising.
There is good news, however. The survey also found the strategies and solutions that students find most effective. By using Internet blockers while revising, taking more exercise, and by breaking down revision into manageable, bite sized-chunks, students are finding ways to cope and succeed.
My favourite Year 11 VCE Chemistry book explains all the concepts you need to know for Units 1 & 2. If you’re in Year 12 and you want to refresh your memory of the essential topics from last year’s course, these are the chapters you should spend the most time reading.
Skip the sections in red;
Read the sections in yellow and make careful annotations;
Study the sections in green because they are assumed knowledge in the Year 12 course.