Tag Archives: chemistry

Try the Most Difficult MCQ that VCAA Ever Asked (2021 edition)

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.

Kennedy College students came 1st out of 248 small schools in the Australia & NZ Science Championships 2021

View the full leaderboard on Education Perfect

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!)

Well done!

VCE Chemistry Written Examination 2020 Analysis

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.

Marks lost by topic. Chapter numbers refer to the Heinemann Chemistry 2 textbook.

Introducing the VCE/VET Statistics Dashboard

I made a free VCE/VET Statistics Dashboard.

Find insights into your favourite subjects here. Data was scraped from VCAA and VTAC using open-source Python. #Python #dataviz

The Boys vs Girls tab and the Dropout Statistics pages are most interesting.

Why are girls 5.5x more than boys likely to drop out of VCE LOTE Arabic?

Try this Python script that scrapes data from the VCAA Research & Statistics page and generates a scatterplot of boys vs girls in each VCE subject. Girls outperform boys in 15 of the 20 most popular VCE subjects.

Data was scraped from the VCAA Research & Statistics page in Python (click here for the source code)

Original code is here:

https://colab.research.google.com/drive/1XFS4Kq5nsYPs5YQIPZrP3q3ehKDrnDgv?usp=sharing

If you’re new to Python, go to the menu bar and click Runtime > Run all.

Then wait for around 20 minutes while this script scrapes data from the VCAA and generates an interactive scatterplot for you. When it’s done, there will be some interesting data files available for download from the file explorer on the left of the screen.

You’ll notice some interesting findings in the scatterplot, including the fact that boys outperform girls in biology, and girls outperform girls in physics! Girls outperform boys in 15 of the 20 most popular VCE subjects with the only exceptions being Chemistry, Biology (only slightly) and all three mathematics subjects.

Feel free to modify this code and repost it. There are some other interesting insights you could glean from the dataset. Enjoy!

High-achieving VCE students are more likely to have chosen Specialist Maths, Latin, Chemistry, Global Politics, Physics and Literature

Data from VCE high achievers list 2018-2020

In this analysis, I defined “high-achieving students” as those who achieve at least 2 study scores ≥40. I then compared this with enrolment data to see how their subject choices differed from that of all students (from VCAA statistics).

Choosing these subjects doesn’t guarantee you a high grade. But it does provide some interesting insight into the patterns of high-achieving students, who are more likely to have chosen Specialist Maths, Latin, Chemistry, Global Politics, Physics and Literature.

All-new Annotated VCE Chemistry Data Book for 2021 Chemistry Course

The data book contains a wealth of information that’s hidden in plain sight. If you know how to read the data book properly, you can:

  • Never lose marks again for not knowing the states of fuels or combustion products
  • Know how to substitute metric prefixes in calculations
  • Learn that amino acids with primary amide side chains (–CONH2) are polar and not basic!
  • and much more…
Slide to preview the annotated VCE Chemistry Data Book

VCE Chemistry written examination paper analysis of marks allocated per chapter

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.

Focus on perfecting your written responses in VCE Chemistry… because that’s where most of the marks are awarded.

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.

I revamped this classic for the VCE Chemistry study design. Download it now: We Lied to You (2019 edition)

we lied to you cover 3d

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).

Why was Bisphenol A (BPA) discontinued in baby bottles?

 

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.

Don’t forget to like and subscribe for more videos from Sincerely, Chemicals.

Annotated VCE Chemistry data book for the 2019 study design

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.

Free download: James Kennedy’s Annotated VCE Chemistry data book 2019 edition

Too big? Download the low resolution (4 Mb) version here

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 jameskennedymonash@gmail.com and I’ll get back to you personally.

making an annotated vce chemistry data book 2019 thumbnail

“Organic” is a farming practice…

 

I started a YouTube channel called Sincerely, Chemicals. It’s inspired by the workshops I’ve been running since 2017 so you can now review the content at home.

Video 2 is below. It’s called “Are Organic Products Safer?”… you already know the answer, but play the 2-minute video to find out why.

If you like these videos, please leave a comment, like and subscribe. That way, I might be encouraged to make more 🙂

P.S. I hope you like the cartoons!

Fighting Chemophobia is now available on Amazon worldwide

fighting chemophobia print run 3 cover
Third edition of Fighting Chemophobia is now available on Amazon.com and Kindle Store

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.

Update (August 2020) – sold out!

Natural pesticides in a cabbage


natural pesticides in cabbage

There exists a myth that organic fruits and vegetables are healthier because they’re free from harmful pesticides. Bruce Ames, one of the key founders of the field of toxicology back in the 1970s, wrote a landmark paper in 1990 called Dietary pesticides (99.99% all natural), in which, he showcased some of the many naturally-occurring pesticides we ingest every day.

Because plants can’t run away, they attack predators with chemical weapons instead. All plants produce natural pesticides called secondary metabolites that deter predators to varying extents. The production of these secondary metabolites is upregulated during predatory attack.

Some of the natural pesticides that plants produce are toxic. Some are carcinogenic. Some studies have even suggested that if synthetic pesticides are not sprayed onto the surface of the crops, as might be the case in some types of organic farming, plants increase their production of natural pesticides to compensate for the resulting increase in herbivory attack.

Proponents of organic food fail to realise that everything we touch, eat and breathe contains miniscule traces of toxins. Our bodies evolved in a pretty dirty environment and can cope with low levels of toxins being ingested. Some studies even suggest that ingesting these tiny amounts of harmful substances might not only be harmless but beneficial to our health.

Contrary to popular belief, natural foods (wild varieties) are not safer, more nutritious nor more delicious than conventionally-farmed foods. Organic farming is an unsustainable luxury that offers no benefit to consumers’ health.

For more information on organic food, check out my latest book, Fighting Chemophobia, which is available by clicking the link below.


Fighting Chemophobia is now available in the Kindle store!
Fighting Chemophobia buy chemistry book

It’s been a while since I posted. I’ve been working on some things that will be revealed in the next few months.