The Chronicles of the Chronicle Flask: 2020

It’s officially time to put 2020 in the bin! Hurrah! And that means it’s time for a round-up of everything on this blog from the last twelve months. It’s not all COVID-19 related, I promise…

Mystery purple crystals

January began with a mystery, about some strange, blueish-purple crystals that were found under a sink. What were they? Well, if you missed it, or you’ve just forgotten, the answer is here

I had no idea at the time, but February was the calm before the storm. I was cheerfully talking about the Pocket Chemist. Have you got one? The post has a discount code, and they’re amazingly useful things. Especially if you’re studying from home…

Everything kicked off in March, and back in those early days everyone was all about the hand-washing. It may not be the burniest or the flashiest, but soap chemistry is some of the oldest chemistry we know. Oh, yes, and wash your hands. Properly.

We were all home learning in April. Or trying to, at least. Lots of chemists started messing about with stuff at home in particular, @CrocodileChemist (aka Isobel Everest give her a follow) created some gorgeous art with home-made indicators. I wrote all about an easy version, made with the classic: red cabbage.

Red cabbage indicator with various household substances

May featured pyrotechnics. Well, everything was on fire, so it seemed apt. Also, it was the thirtieth anniversary of the publication of the novel, Good Omens.

It was back to COVID-19 science in June, because everyone was talking about dexamethasone a well-known, readily available and, crucially, cheap steroid that has been shown to help patients with the most severe symptoms. Want to know more about its history? Check out the post.

By July nothing was over, but we’d definitely all had enough. So it was time to talk about something completely different. What better than a post all about sweet things, to mark national lollipop day?

In August the folks at Genius Lab Gear sent me an awesome set of Science Word Magnets. Do you need a set of these for when you finally make it back to a whiteboard? Check out this post for a discount code

September was all about skin chemistry

There’s evidence that low vitamin D levels are correlated with worse COVID-19 outcomes and, in the UK, we can’t make it in our skin in the winter months so September was all about vitamin D. Want to know more? Read all about sunshine and skin chemistry.

It’s Mole Day on the 23rd of October, so I did some ridiculous and, frankly, slightly disgusting calculations. Did you know that if we drained the blood out of every, single human on the planet, we’d only have about half a mole of red blood cells? You do now.

In November I went back to cleaning chemistry. Well, we had all been stuck at home for a while. This time, it was ovens. Why is cleaning ovens such hard work? Why do we use the chemicals we use? I explained all that. Read on!

Annnnd that brings us to December, and the STEM Heroes Colouring Book — a project I’m super proud to be a part of. So, hey, there’s been some good stuff!

Here’s to the end of 2020, and let’s hope that 2021 brings us some good things. It has to, surely? January traditionally brings a health scare, but no one’s doing that in 2021, are they? Are they? I guess we’ll find out soon… lots of love to everyone, stay safe, and stay well!


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Hydrogen peroxide: another deadly alternative?

I’m sure most people have heard of hydrogen peroxide. It’s used as a disinfectant and, even if you’ve never used it for that, you probably at least know that it’s used to bleach hair. It’s where the phrase “peroxide blonde” comes from, after all. Hydrogen peroxide, and its formula, is so famous that there’s an old chemistry joke about it:

(I have no idea who to credit for the original drawing – if it’s you, leave me a message.)

To save you squinting at the text, it goes like this:
Two men walk into a bar. The first man says, “I’ll have some H2O.”
The second man says, “I’ll have some H2O, too.”
The barman brings the drinks. The second man dies horribly.

Now I think about it, it’s not a terribly funny joke.

Hydrogen peroxide has an extra oxygen atom in the middle.

Never mind. You get the idea. H2O2 (“H2O, too”) is the formula for hydrogen peroxide. Very similar to water’s formula, except with an extra oxygen atom in the middle. In fact, naturopaths – purveyors of alternative therapies – often refer to hydrogen peroxide as “water with extra oxygen”. But this is really misleading because, to torture a metaphor, that extra oxygen makes hydrogen peroxide the piranha to water’s goldfish.

Water, as we know, is pretty innocuous. You should try not to inhale it obviously, or drink more than about six litres in one go, but otherwise, its pretty harmless. Hydrogen peroxide, on the other hand, not so much. The molecule breaks apart easily, releasing oxygen. That makes it a strong oxidising agent. It works as a disinfectant because it basically blasts cells to pieces. It bleaches hair because it breaks down pigments in the hair shaft. And, as medical students will tell you, it’s also really good at cleaning up blood stains – because it oxidises the iron in haemoglobin to Fe3+, which is a pale yellow colour*.

Dilute hydrogen peroxide is readily available.

In its dilute form, hydrogen peroxide is a mild antiseptic. Three percent and even slightly more concentrated solutions are still readily available in high-street pharmacies. However, even these very dilute solutions can cause skin and eye irritation, and prolonged skin contact is not recommended. The trouble is, while it does destroy microbes, it also destroys healthy cells. There’s been a move away from using hydrogen peroxide for this reason, although it is still a popular “home” remedy.

More concentrated** solutions are potentially very dangerous, causing severe skin burns. Hydrogen peroxide is also well-known for its tendency to react violently with other chemicals, meaning that it must be stored, and handled, very carefully.

All of which makes the idea of injecting into someone’s veins particularly horrific.

But this is exactly what some naturopaths are recommending, and even doing. The idea seems to have arisen because hydrogen peroxide is known to damage cancer cells. But so will a lot of other dangerous substances – it doesn’t mean it’s a good idea to inject them. Hydrogen peroxide is produced by certain immune cells in the body, but only in a very controlled and contained way. This is definitely a case where more isn’t necessarily better.

The use of intravenous hydrogen peroxide appears to have begun in America, but it may be spreading to the UK. The website yestolife.org.uk, which claims to empower people with cancer to “make informed decisions”, states “The most common form of hydrogen peroxide therapy used by doctors calls for small amounts of 30% reagent grade hydrogen peroxide added to purified water and administered as an intravenous drip.”

30% hydrogen peroxide is really hazardous stuff. It’s terrifying that this is being recommended to vulnerable patients.

Other sites recommend inhaling or swallowing hydrogen peroxide solutions, both of which are also potentially extremely dangerous.

If anyone ever suggests a hydrogen peroxide IV, run very fast in the other direction.

In 2004 a woman called Katherine Bibeau died after receiving intravenous hydrogen peroxide treatment from James Shortt, a man from South Carolina who called himself a “longevity physician”. According to the autopsy report she died from systemic shock and DIC – the formation of blood clots in blood vessels throughout the body. When her body arrived at the morgue, she was covered in purple-black bruises.

Do I need to state the obvious? If anyone suggests injecting this stuff, run. Run very fast, in the other direction. Likewise if they suggest drinking it. It’s a really stupid idea, one that could quite literally kill you.


* As anyone who’s ever studied chemistry anywhere in my vicinity will tell you, “iron three is yellow, like wee.”


** The concentration of hydrogen peroxide is usually described in one of two ways: percentage and “vol”. Percentage works as you might expect, but vol is a little different. It came about for practical, historical reasons. As Prof. Poliakoff comments in this video, hydrogen peroxide is prone to going “flat” – leave it in the bottle for long enough and it gradually decomposes until what you actually have is a bottle of ordinary water. Particularly in the days before refrigeration (keeping it cold slows down the decomposition) a bottle might be labelled 20%, but actually contain considerably less hydrogen peroxide.

What to do? The answer was quite simple: take, say, 1 ml of hydrogen peroxide, add something which causes it to decompose really, really fast (lots of things will do this: potassium permanganate, potassium iodide, yeast, even liver) and measure the volume of oxygen given off. If your 1 ml of hydrogen peroxide produces 10 ml of oxygen, it’s 10 vol. If it produces 20, it’s 20 vol. And so on. Simple. 3% hydrogen peroxide, for the record, is about 10 vol***. Do not mix up these numbers.


*** Naturally, there are mole calculations to go with this. Of course there are. For A-level Chemists, here’s the maths (everyone else can tune out; I’m adding this little footnote because I found this information strangely hard to find):

Hydrogen peroxide decomposes as shown in this equation:
2H2O2 –> 2H2O + O2

Let’s imagine we decompose 1 ml of hydrogen peroxide and obtain 10 mls of oxygen.

Assuming the oxygen gas occupies 24 dm3 (litres), or 24000 mls, at standard temperature and pressure, 10 mls of oxygen is 10 / 24000 = 0.0004167 moles. But, according to the equation, we need two molecules of hydrogen peroxide to make one molecule of oxygen, so we need to multiply this number by two, giving us 0.0008333 moles.

To get the concentration of the hydrogen peroxide in the more familar (to chemists, anyway) mol dm-3, just divide that number of moles by the volume of hydrogen peroxide. In other words:

0.0008333 mols / 0.001 dm3 = 0.833 mol dm-3

If you really want to convert this into a percentage by mass (you can see why people stick with “vol” now, right?), then:

0.833 mol (in the litre of water) x 34 g mol-1 (the molecular mass of H2O2)
= 28.32 g (in 1000 g of water)

Finally, (28.32 / 1000) x 100 = 2.8% or, rounding up, 3%

In summary (phew):
10 vol hydrogen peroxide = 0.83 mol dm-3 = 3%


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