Some multiple choice questions (approximately 2 out of every 30) are “tricky” – that is, they contain a distractor that students choose more frequently than the correct answer.
This collection of 10 multiple choice questions is entirely comprised of questions where students did worse than guessing (in other words, <25% of students chose the correct answer). One of these questions was so tricky that only 8% got it right.
Try these questions then scan the QR code at the end for the solutions.
My Kennedy College students worked tirelessly to climb to the top of the small schools (≤50 students) leaderboard for the Education Perfect Science Championships 2021. The competition is open to schools of any size in Australia and New Zealand. We came first out fo 248 small schools who participated.
I’m very proud of their achievement.
While this competition was online, there will probably be more opportunities to compete with other schools face-to-face in 2022 (depending on covid restrictions!)
The pandemic turned VCE Chemistry upside-down. Stoichiometry, traditionally a difficult topic, was the best-answered of all. Chromatography, traditionally an easy topic, was the most difficult for the class of 2020.
Most noticeable is the increase in “difficult” topics highlighted red in the chart above. (For a comparison with the 2013 & 2014 VCE Chemistry written examinations, click here.)
Unbelievably, the Victorian state average score in the 2020 VCE Chemistry written examination was a FAIL at just 47.9%.
Disruptions to learning caused by the pandemic could help explain why the VCAA is considering making the VCE Chemistry curriculum substantially easier from 2023 onwards. If the educational effects of the 2020 pandemic really do linger for most of this decade then making the curriculum easier fails to tackle the root of the problem, which is the loss of quality study-hours. I believe the only correct remedy is to provide current students with extra training and support to make up for the pandemic… not to drop the bar so low that our students cannot compete on the world stage.
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.
This book is a collection of lies we taught to our Year 12 Chemistry students in their graduation year.
The 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 wrote this book to demonstrate the overwhelming complexity of Chemistry and the consequential need to make appropriate omissions and generalisations during our teaching as we tailor our lessons to the appropriate year level of students.
Rules taught as true usually work 90% of the time in this subject. Chemistry has rules, exceptions, exceptions to exceptions and so on. You’ll peel pack these layers of rules and exceptions like an onion until you reach the core, where you’ll find physics and specialist maths.
Click here to download We Lied to You (2019 edition).
Bisphenol A, or BPA, is used to line food cans and also to make strong plastic baby bottles. Eating large amounts of canned food – particularly canned soups or drinking hot liquids from baby bottles – can result in elevated amounts of BPA being detected in people’s urine. BPA acts as an estrogen mimic – albeit a very weak one – and some research has suggested a link between large doses of BPA and an increase of blood pressure. While this does sound worrying, remember that the dose is extremely important and that the molecules of BPA that do leech into food are too few to have any measurable effect.
The United States Food and Drug Administration (the FDA) conducted a four-year review of over 300 scientific studies and concluded that the traces of BPA that do migrate into canned food are so tiny that they have no effect on human health.
The decision to abandon the use of BPA in baby bottles was therefore based on public pressure not based on safety or on scientific evidence.
The science never suggested there was any safety concern with BPA.
Each year, the VCAA subtly upgrades the VCE Chemistry data book. Each year, I print it and annotate it to show students the wealth of useful information hidden within it (most of which, is in plain sight).
This year, the VCAA has changed some “constants” and added some interesting functional groups to the spectroscopy tables. Smaller things are changed, too. All the protons in the 1H NMR table are now in bold; not just the ambiguous ones.
Start using this annotated version of the data book for your year 11 and year 12 chemistry homework exercises. While you can’t take this annotated version into the final examination (or into most SACs), seeing the annotations frequently throughout the two years will help you find things faster in the final examination.
Do you have feedback? Any comments? Do you require 1-to-1 chemistry tutoring? Email me at firstname.lastname@example.org and I’ll get back to you personally.
After several hurdles, I’m happy to announce that Fighting Chemophobia is now available on Amazon in both paperback and Kindle editions for international delivery. Amazon.com and three other independent online book vendors have signed up to stock Fighting Chemophobia.
Buy your copy by clicking the links below – or search Amazon.com or your Kindle device for Fighting Chemophobia to download the book.
Signed copies are of this new third edition are of course still available via this website. Click the PayPal link below to order your signed copy.
I’ve been working on some exciting things in the last few months. Watch this space for teasers.
The second batch of Fighting Chemophobia books are finished! After a long search, we have finally found two great companies for printing and distribution in China. Dianzan design and printing company has laid the book out with great care and precision and turned Fighting Chemophobia into an excellent-quality product in both hardback and paperback editions. The 80 gsm Dowling paper feels great, and there are even some full-page colour images scattered throughout the book. Shunfeng Express is handling cheap, quick shipping and is currently achieving 2-day deliveries within China. They predict 7-day delivery times internationally.
This second batch is higher quality than the first. I’m sure you’ll love what these people have produced.
Working with a publisher could have saved me the search for an editor, a printer, a distributor, a marketer and a translator. Self-publishing has been more rewarding in this regard: not only have I selected the people I’ve worked with to bring this book to completion but I’ve probably learned more this way about the process of writing, editing, printing, binding, marketing and distributing a book than if a publisher had handled the entire process on my behalf.
You can buy your signed copy of the second batch of Fighting Chemophobia using the PayPal link below. Click subscribe on this page to receive future (approximately fortnightly) email updates.
Chemophobia is an irrational fear of chemicals. It includes the fear of sugar in food, formaldehyde in shampoo and aluminium in vaccines. Fitness bloggers, quack doctors and even small cosmetic companies take advantage of these quirks to sell fake-natural products at elevated prices. Almost always, the same people who spread a fear of ‘chemicals’ also have ‘chemical-free’ products for sale.
Some companies sell “natural”, “organic” and “chemical-free” products to combat the supposed onslaught of chemical pollution in conventional consumer products. Most of these alternative products are no less synthetic, and no safer, than conventional versions despite commanding much higher prices.
Chemophobia is spreading despite our world becoming a cleaner, safer place. People are becoming healthier, and product safety regulations are becoming stricter. The supposed onslaught of chemicals that these special interest groups describe simply isn’t happening.
Perpetrators of chemophobia create unnecessary guilt, stress and anxiety as consumers worry about making the right choices for their family. Consumers are the victims in this battle as pro-natural and anti-natural businesses spread fear about each other’s products.
This book analyses psychological quirks, evolved millennia ago, that prime us to fall victim to chemophobic ways of thinking such anorexia, a fear of vaccines, a fear of fluoridation or a dangerous fear of synthetic medicines. It explores how consumers, teachers, doctors, lawmakers and journalists can fight chemophobia by tackling the social issues that underpin it.
Order your signed copy of Fighting Chemophobia now
Unlike purple and pink pigments, which were rare and expensive enough to be reserved for royalty and high-ranking clergy, yellow pigments were abundant throughout ancient history. Yellow ochre, a powdery mixture of iron oxides, has been used in cave paintings around the world for up to 80,000 years and was still being used by artists in the early nineteenth century. Saffron and turmeric were also used as yellow dyes throughout ancient history. Vincent van Gogh was using mineral yellow pigments such as cadmium yellow and chrome yellow in his mid-nineteenth century paintings. By the mid-nineteenth century, people looking for yellow pigments already had plenty of options. Despite there being no pressure from consumers for a new yellow dye, chemists trying to replicate the fame and fortune that mauveine brought to William Perkin in 1856 were experimenting eagerly in pursuit of that goal.
In 1861, Mêne was reacting aniline with cold nitrous acid to produce a diazonium salt solution. He then added more aniline to the resulting salt solution and shook the flask vigorously and noticed a yellow precipitate formed at the bottom of the flask, which would later become known as ‘aniline yellow’ – the first ‘azo dye’. 
The reaction mixture must be kept cool (at around 5 °C) because different temperatures cause different products to form. If the same reactants are mixed warm, then smelly liquid phenol and inert nitrogen gas are formed, both of which are colourless, and neither of which are useful as pigments!
At the time, the ‘aniline yellow’ powder he discovered was considered useless because it didn’t dissolve in water. However, it did dissolve very well in oil. The dye eventually gained some niche uses as a microscopy stain (like fuchsine) but was never utilised by the garment or pigment industry.
After staying relatively unused for over a hundred years, aniline yellow left an unfortunate legacy for itself by becoming the culprit molecule in the Spanish ‘Toxic Oil scandal’ of 1981. A batch of Spanish rapeseed oil had been denatured (deliberately adulterated) with 2% aniline yellow so the company could report it as “machine oil” and take advantage of certain tax breaks. One local refinery obtained the denatured rapeseed oil and attempted to remove the aniline yellow dye so they could sell it on as “pure olive oil” on the market for profit. They sold the oil around much of north-western Spain in unlabelled 5-litre plastic containers.
The first casualty was an eight-year-old boy who died upon arrival at a hospital in Madrid on May 1st, 1981. The rest of his family then presented with an unusual set of symptoms: headache, fever, itchy scalp, lethargy and interstitial lung disease. The hospital diagnosed the family with “atypical pneumonia” and treated them all with antibiotics but they showed little improvement. 
Across Spain, 20,000 patients presented with similar symptoms within one month of the incident. Thinking that an unexplained pneumonia outbreak was unfolding, a children’s hospital in Madrid conducted a randomised, double-blind controlled clinical trial on the effectiveness of the antibiotic erythromycin, which is particularly effective on infections of the respiratory system.  Unfortunately, they found no difference in recovery or mortality rates between the treated group and the control group and decided to keep looking for potential treatments.
Attempting all avenues, the researchers conducted lifestyle surveys on many patients, which included (among many other things) questions about cooking oil. Sadly, even though the source of the problem was staring them in the face, the results of the oil usage survey questions came back “inconclusive”. 
A baby ultimately solved the puzzle. Prognosis for young children was generally worse than for adults after they contracted the strange set of symptoms. Oddly, babies under six months were unaffected even if the entire rest of the family had presented with the pneumonia-like symptoms. Their infants were completely symptom-free. When one baby did get sick, however, this prompted deep and urgent questioning of the parents involved to find out what they did differently from others. One unusual aspect of the baby’s upbringing was that the baby’s grandmother had been ‘supplementing’ baby’s formula powder with cooking oil that was sold in an unlabelled 5-litre plastic container. 
Spanish government agencies acted quickly. The Ministry of Health and Consumer Affairs issued a recall of all oil sold in unlabelled plastic bottles within 40 days of the first casualty reporting with symptoms (the 8-year-old boy). Rates of patients presenting with symptoms of Toxic Oil Syndrome, as it would later be called, plummeted after the recall was announced on June 10th, 1981.
The aniline yellow had all been removed. The problem was a side-reaction, completely unknown to the scientists who were purifying the “machine oil”, that formed a new, harmful molecule that was large enough to escape their detection methods.
The molecule responsible for Toxic Oil Syndrome is called “OO PAP” in scientific literature. Visual inspection of OO PAP’s structure reveals that it’s quite simply an olive oil triglyceride molecule (triolein) with one of its three fatty acid tails replaced with a large aniline group.  When the rapeseed oil was adulterated with 2% aniline yellow to disguise it as “machine oil”, some of the aniline yellow molecules didn’t just blend in with the oil but reacted chemically with it to make OO PAP molecules. ITH, the company who sold the de-adulterated product as “pure olive oil”, was likely unaware of this chemical reaction, and therefore (we assume) also unaware of the poisonous OO PAP that had formed in the oil. While ITH successfully removed the aniline yellow, they failed to remove the OO PAP molecules, which escaped their filtration techniques.  Sadly, hundreds of people died and 20,000 more were made ill from OO PAP poisoning, and financial damage was estimated by El País newspaper to be 2 billion pesetas (around 16 million US dollars today).  Just like the scandal of the pink fuchsine socks, government and industry were forced to work together to respond quickly to a growing public crisis.
Every chemical – regardless of whether it’s found naturally or created synthetically – has the potential to be beneficial, harmful or harmless depending on the dosage and the way that it’s used. Aniline yellow, like all other chemicals, is incredibly useful when used correctly. It’s a fantastic microscopy stain but totally unsuitable for culinary use.
Today, people use aniline yellow to dye specimens for viewing under a light microscope. Aniline yellow’s dangers are stated clearly on its safety data sheets: handling it today requires training, permits, safety glasses, gloves and a lab coat to avoid all contact with skin and eyes. Now that chemistry has given us a better understanding of the aniline yellow, nobody dare use it to dye foodstuffs. 
The “deficit model” is a widely criticized theory that suggests that people who harbor attitudes of negativity or indifference towards science (in this case, chemistry) do so because they are uninformed about the topic (Chinese: 无知).
People’s misinformation might come from a lack of interest, a lack of exposure or an experience of poor science outreach in the past, where incorrect messages were delivered.
The “deficit model” stipulates that if people knew more about science, they’d naturally become more interested in it. Unfortunately, it doesn’t always seem to work, and the ‘model’ is subjected to routine criticism.
Criticisms of the “deficit model”
It is patronizing to the public, which alienates them further from science
It implies that there is only one coherent, correct narrative of ‘science’
It implies that people who don’t like science are misinformed about it
Learning science isn’t always fun
Being forced to learn something they’re not interested in could reinforce negative attitudes towards science
The public is too varied to attempt to give a “one size fits all” theory of science outreach
It ignores the fact that members of the public have individual preconceived ideas about science before they’re introduced to new science information
It relies too much on monologue/lecturing the public rather than engaging them in dialogues
Employ alternatives to the “deficit model”
Critics of the “deficit model” tend to advocate solutions that involve dialogue (rather than monologue) with the public. Dialogue works better when the particular public audience in question has pre-existing views about the scientific topic being discussed (called ‘affected/partisan’ public groups).
There are four main types of ‘public’ audiences. The table below summarizes each of these types and how to engage with them, and is adapted from Canek Phillips report from 2013.
The general public consists of people with diverse views that represent a cross-section of society. In a group, these views cancel out somewhat, hiding the deviation of views. The “deficit model” of monologue delivery is an effective way to engage such a group.
The pure public is a group of people who have no pre-existing ideas about the topic being discussed. The “deficit model” can engage these audiences as well.
The affected public can only be engaged if their pre-existing views are acknowledged and respected beforehand. Dialogue is an excellent way of doing this. Examples of dialogue-based approaches include science shops, public hearings, citizen judies, stakeholder consultations and focus groups.
The partisan public is sometimes led by charismatic leaders or lobby groups. Their views might have been shaped by influential figures (e.g. Mercola, Food Babe) and the pre-existing views (misconceptions) delivered in this way need to be debunked through respectful dialogue rather than monologue.
In short, before telling your audience something, find out whether they have any pre-existing ideas about that topic. If they don’t, then go ahead with a monologue delivery. If they do, then launch a two-way discussion with them, in which you listen and respect their views. Only then, will they respect your opinion as well. ♦