Examination reports are very useful but most students don’t read them. I’ve scoured the examination reports from 2017, 2018 and 2019 and analysed how many marks were awarded for each topic of the VCE Chemistry course, and recorded what percentage of students got these right. As usual, this revealed that VCAA asks more questions on topics that students frequently get wrong.
Tip for students: focus more of your attention on the red topics in the chart above.
Chapter numbers refer to those used in the Heinemann Chemistry 2 textbook.
Students obsess over significant figures and mole calculations… but these are only worth 1 and 16 marks, respectively in the final written examination. Over two-thirds of the marks in the VCE Chemistry written examination are awarded for written responses where calculations are not necessary.
Tip for students: focus on perfecting your written responses such as explanations of bonding, chromatography, protein structures, and, most importantly, critiquing experimental designs.
Plotting a graph of ΔATAR/study score vs ATAR gives an interesting curve: students whose ATARs are around 50 have the most to gain from an additional study score point. Above about 90, the incremental ATAR gain from a single extra study point is probably below the margin of error given the way in which ATARs are calculated.
Tip for students: check the entry requirements for your course and make sure you meet those first. If your requires, for example, a particular score in the UMAT or in English, make sure you get that score. If your course requires a particular ATAR, make sure you get that, too. Remember that these scores are just entry requirements for undergraduate courses; not indicators of self-worth.
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 collection of reliable formulae that I have been using to answer VCE Chemistry questions while teaching and tutoring around Melbourne.
There are 76 formulae on 8 pages. At least 10 of these formulae aren’t in the three main chemistry textbooks. Orders are shipped in A4-sized booklet that resembles the VCAA Data Booklet.
Orders from schools, students and tutors are all welcome. Price includes free international delivery and a 10% voucher for the T-shirt store.
James Kennedy achieved outstanding A-level results in 2006 in Maths, Chemistry, Physics and Biology. Those excellent grades (which equate to an ATAR of 99+) earned him a BA (Hons) degree and a Masters degree in Natural Sciences from the University of Cambridge.
Shortcut formulae were just one of the techniques James used to pass his A-level exams and get into Cambridge. Along with structured revision, revision guides, practice papers and study notes on wall-cards, James used shortcut formulae to save precious time in the examination hall. You can get your own copy of these original shortcut formulae – revised and updated for the 2017-2021 VCE Chemistry course – for just $55 including free international shipping. Click here to get your copy.
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!
Recall from last week that our Periodic Table Smoothie contains the following species:
Amount present (moles)
Pressure: 718 kPa Temperature: 350 °C
Reactions of nitrogen in our 10-litre vessel
Our freshly-added 1.00 mol of nitrogen gas, N2(g), reacts with hydrogen gas to make ammonia in the following reversible (equilibrium) reaction. We will assume that the interior metal surface of the vessel is a suitable catalyst for this reaction (e.g. iron).
There are three other reactions below that might have occurred at higher temperature, but I’ve chosen not to raise the temperature of the vessel at this point. Rather, we’ll keep it at 350 °C to keep things manageable.*
*I was tempted at this point to elevate the temperature of our vessel to 500 °C so that the second reaction could take place as well. This would produce copious amounts of smelly ammonia gas, which would allow for larger quantities of interesting organic compounds to be produced later on. To keep our simulation safe and (relatively) simple, I’ve decided to keep the vessel at 350 °C. Interesting compounds organic will still form – only in smaller amounts.
The ammonia reaction above (the first equation) is actually an equilibrium reaction. That means that the reactants are never completely used up, and the yield is not 100%.
Recall from Le Châtelier’s principle that removing product from an equilibrium reaction causes the position of equilibrium to shift to the right, forming more product. This is because:
“If an equilibrium system is subjected to a change, the system will adjust itself to partially oppose the effect of the change.” – Le Châtelier’s principle
There are three reactions that will remove ammonia from our vessel while it’s being produced, and I’ve put all three of these into the simulation. One of these is the reverse of the reaction above (producing hydrogen and nitrogen gases) and the other two are described below. Let’s take a look at those other two reactions.
With what will the ammonia react in our vessel?
Ammonia can undergo the following reactions with the other things in our vessel**
**The ammonia does react with methane and beryllium as well, but only at temperatures of 1200 °C and 600 °C, respectively.
Two compounds will be formed: lithium amide and borazine. Lithium amide reacts with nothing else in the vessel, so the reaction chain stops there. Borazine, on the other hand, is much more interesting.
We’ve made borazine!
Borazine is a colourless liquid at room at temperature. It boils at 53 °C and has a structure that resembles that of benzene.
Because of the electronegativity difference of about 1.0 between the B and N atoms in the ring, borazine has a mesomer structure:
Like benzene, there is partial delocalisation of the lone pair of electrons on the nitrogen atoms.
Borazine polymerises into polyborazine!
Fascinatingly, borazine polymerises into polyborazine at temperatures above 70 °C, releasing an equal number of moles of hydrogen gas. Polyborazine isn’t particularly well-understood or well-documented, but one recent paper suggested it might play a role in the creation of potential ceramics such as boron carbonitrides. Borazine can also be used as a precursor to grow boron nitride thin films on surfaces, such as the nanomesh structure which is formed on rhodium.
Like several of the other compounds we’ve created in our Periodic Table Smoothie, polyborazine has also been proposed as a hydrogen storage medium for hydrogen cars, whereby polyborazine utilises a “single pot” process for digestion and reduction to recreate ammonia borane.
The hydrogen released during the polymerisation process will then react further with a little bit of the remaining nitrogen to produce a little more NH3(g) – but not much. Recall from earlier that the ammonia reaction is an equilibrium one, and the yield of NH3(g) at pressures under 30 atmospheres is very low. Pressure in our vessel is still only around 7 atmospheres.
Once polymerised, this would form about 12 grams of polyborazine:
As far as I’m aware, no further reactions will take place in the vessel this week.
Conclusion after adding 1.00 mole of nitrogen gas
Amount in mol
Pressure: 891 kPa (higher than before due to the addition of nitrogen gas) Temperature: 350 °C (vessel is still being maintained at constant temperature)
Next week, we’ll add a mole of oxygen gas to the vessel. Warning: it might explode.
Stock, Alfred and Erich Pohland. “Borwasserstoffe, VIII. Zur Kenntnis Des B 2 H 6 Und Des B 5 H 11”. Berichte der deutschen chemischen Gesellschaft (A and B Series) 59.9 (1926): 2210-2215. Web.
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.
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.
RTQ! This is one of the most common sources of errors in Chemistry examinations. When I sat 2014’s VCE Chemistry examination, I lost 5 marks in the paper for not reading the question! Your teachers will have told you to ‘read the question’ or ‘RTQ’ as well.
Task word errors can be avoided in two ways. First, learn the exact meanings of each task word. This is particularly important for EAL Chemistry students. Second, highlight the task words in a question (just as you would highlight the important information in a complicated titration question).
For example: “Explain how the different intermolecular forces in butane and butan-1-ol give these two compounds different boiling points. 3 marks”
In your answer, you will need to explain the effect of intermolecular forces. This means you’ll need to write why the butan-1-ol forms hydrogen bonds (due to the polar nature of the hydroxyl group) whereas butane forms only dispersion forces with its surrounding molecules (due to the non-polar nature of the molecule). You’ll also need to make some kind of comparison (which is hinted at by the word, ‘different’) in order to get all 3 marks.
Example 3-mark answer: “Butan-1-ol forms intermolecular hydrogen bonds with the surrounding molecules due to the polar nature of the hydroxyl group (O-H bond). Butane forms only dispersion forces with its surrounding molecules due to the non-polar nature of the molecule. Hydrogen bonds are stronger than dispersion forces and thus require more energy to break. This results in a higher boiling point for butan-1-ol than for butane”.
One mark would be awarded for each of:
Explaining the intermolecular bonding of butan-1-ol
Explaining the intermolecular bonding of butane
Comparing the relative strengths of the two and relating this to boiling points
In a 2-mark answer, the student might omit the comparison step:
Example 2-mark answer: “Butan-1-ol forms intermolecular hydrogen bonds with the surrounding molecules due to the polar nature of the hydroxyl group (O-H bond). Butane forms only dispersion forces with its surrounding molecules due to the non-polar nature of the molecule.”
In a 1-mark answer, the student might only mention one of the two molecules, or might only make a comparison without explaining whythese two compounds display different types of intermolecular forces.
Example 1-mark answer: “Hydrogen bonds formed by butan-1-ol are stronger than dispersion forces formed by butane and thus require more energy to break. This results in a higher boiling point for butan-1-ol than for butane”.
In that latter example, the student didn’t explain the reasons for the differences in intermolecular bonding – they merely stated them.
Write the value of a number (include equations)
Write the similarities and differences between
Write arguments for and against
Write the exact meaning of
Write details about (a thing or a process)
Write reasons for and against
Write the differences between two or more things
Write details to give the reader an understanding of
Write (sometimes by doing calculations)
Write which one
Write something and draw a labelled diagram as well
Write which one (usually on a given diagram)
Write a list
Write a summary
Write a reason for a phenomenon
To what extent
Write whether a reaction is complete (→) or incomplete (↔).
Watch task words in the examination… and make sure you answer the question!
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.