Tag Archives: Sodium bicarbonate

The Chronicles of the Chronicle Flask: 2017

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We’ve made it! Not only to 2018 (which was starting to look doubtful earlier in the year), but also to the Chronicle Flask’s 100th post. Which doesn’t seem that many, really, but since posts on here frequently run to 1500 words, that adds up to a rather more impressive-sounding 150,000 words or so. I mean, that’s like… half a Brandon Sanderson novel. Oh.

Anyway, it’s time for a yearly round-up. Here goes!

Last January I began with a post about acrylamide. We’d all been enjoying lots of lovely crispy food over Christmas; it was time to tell us about the terrible dangers of such reckless indulgence. The newspapers were covered with pictures of delicious-looking chips, toast and roast potatoes alongside scary headlines such as:  “Crunchy toast could give you cancer, FSA warns”. The truth was not quite so dramatic. Acrylamide does form when foods are cooked to crispiness, and it is potentially harmful, but the quantities which form in food are tiny, and very unlikely to cause you any serious harm unless you literally live on nothing but burnt toast. The FSA (Food Standards Agency) hadn’t significantly revised their guidelines, it turned out, but were in fact only suggesting that the food industry should be mindful of acrylamide levels in food and seek to reduce them as much as possible. That wouldn’t have made for quite such a good “your food is going to killllll you!” story though, I suppose.

In February the spikey topic of vaccination came up. Again. Vaccines are awesome. They protect us from deadly diseases. No, I don’t want to hear any nonsense about “Big Pharma“, and I definitely don’t want to hear how “natural immunity” is better. It’s not. At best, it might provide a similar level of protection (but not in every case), but it comes with having to suffer through a horrible, dangerous disease, whereas vaccination doesn’t. It ought to be a no-brainer. Just vaccinate your kids. And yourself.

It was Red Nose Day in the UK in March, which brought some chemistry jokes. Turns out all the best ones aren’t gone, after all. Did you hear about the PhD student who accidentally cooled herself to absolute zero? She’s 0K now.

April brought a post which ought to have been an April Fool’s joke, but wasn’t. Sceptics often point out that homeopathy is just sugar and water, but the trouble is, sometimes, it’s not. There’s virtually no regulation of homeopathy. As far as I’ve been able to establish, no one tests homeopathic products; no one checks the dilutions. Since a lot of the starting materials are dangerously toxic substances such as arsenic, belladona, lead and hemlock, this ought to worry people more than it does. There has been more than one accidental poisoning (perhaps most shockingly, one involving baby teething products). It really is time this stuff was banned, maybe 2018 will be the year.

In May I turned to something which was to become a bit of a theme for 2017: alkaline water. It’s not so much that it doesn’t do anything (although it really doesn’t), more the fact that someone is charging a premium for a product which you could literally make yourself for pennies. It’s only a matter of dissolving a pinch of baking soda (sodium bicarbonate) in some water.

June brought a selection of periodic tables because, well, why not? This is a chemistry blog, after all! And now we’ve finally filled up period seven they do have a rather elegant completness. 2019, by the way, has just been announced as the International Year of the Periodic Table of Chemical Elements, to coincide with IUPAC’s 100th anniversary and the 150th anniversary of Mendeelev’s discovery of periodicity (his presentation, The Dependence Between the Properties of of the Atomic Weights of the Elements, was made on 6th March 1869). Looks like 2019 will be an exciting year for chemists!

In July it was back to the nonsense of alkaline diets again, when Robert O. Young was finally sentenced to 3 years, 8 months in custody for conning vulnerable cancer patients into giving him large sums of money for ineffective and dangerous treatments. Good. Moving on.

August brought me back to a post that I’d actually started earlier in the year when I went to a March for Science event in April. It was all about slime, and August seemed like a good time to finally finish it, with the school holidays in full swing – what could be more fun on a rainy day at home than making slime? Slime was a bit of a 2017 craze, and there have been a few stories featuring children with severely irritated skin. But is this likely to be caused by borax? Not really. Turns out it’s actually very safe. Laundry detergents in general, not so much. In short, if you want to make slime the traditional way with PVA glue and borax, fill your boots. (Not really – your parents will be uninpressed.)

In September it was back to quackery: black salve. A nasty, corrosive concoction which is sold as a cancer cure. It won’t cure your cancer. It will burn a nasty great big hole in your skin. Do not mess with this stuff.

October carried on in a similar vein, literally. This time with a piece about naturopaths recommending hydrogen peroxide IVs as a treatment for lots of things, not least – you guessed it – cancer. Yes, hydrogen peroxide. The stuff you used to bleach hair. Intraveneously. Argh.

The puking pumpkin!

The end of the month featured a far better use for hydrogen peroxide, that of the puking pumpkin. Definitely one to roll out if, for any reason, you ever find yourself having to demonstrate catalysis.

November brought us, somewhat unseasonally, to tomatoes. Where is the best place to store them? Fridge or windowsill? Turns out the answer involves more chemistry than you might have imagined.

And then, finally, December. Looking for a last-minute Christmas gift? Why not buy a case of blk water? I mean, other than it’s an exorbitantly priced bottle of mysterious black stuff which doesn’t do any of the things it claims to do, and might actually get its colour from coal deposits, that is.

And that, dear friends and followers, is it for 2017! Happy New Year! Remember to be sceptical when the inevitable “deadly food” story appears in a few weeks….

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Are you a chemist and you didn’t know it?

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When I tell people that I’m a chemist, I often get an “oooh, I was really bad at that at school” type response. It’s surprising the number of people that think chemistry has nothing whatsoever to do with their daily lives. Memorably, one acquaintance of an acquaintance (I wouldn’t go so far as to say friend of a friend) once even proclaimed, quite proudly, that the whole of science had nothing to do with her, and she lived her life entirely without it. I was so gobsmacked I didn’t really know where to start, and trust me, that doesn’t happen often.

washing-hands--soap-jpgSo with that in mind, here are five bits of chemistry you do every day. Or at least regularly. You’re a chemist and you didn’t know it!

1. Wash your hands.
Well, we all hope you do this one every day anyway. Soap is very clever stuff. It’s one of the oldest bits of chemistry there is, going back thousands of years, when people first discovered that if they washed their pots with the ashes of cooking fires they got a better result. Soap is made by a process called saponification, where fats are mixed with strong alkalis (traditionally lye: sodium or potassium hydroxide). The fats break apart and form fatty acid salts. What’s clever about those, is that they have a water-loving end (the salt bit) and a water-hating end (the fatty acid bit). So they can grab onto both, and hold the water and oil together. That’s what you do every time you use soap: the dirt ingrained in oil on your skin (nice) can, with the help of those lovely soap molecules, mix with water and so be washed away. Brilliant!

2. Drink a pH indicator.
‘What’ I hear you cry, ‘I do no such thing!’ Ah but do you drink tea (the black kind)? If so, then you do, even if you’ve never noticed. Have you ever put lemon in your tea instead of milk? If not, and you have tea and lemon juice (bottled is fine) in your house, go and try it now. The colour change is really quite lovely to watch. Lemon juice is a source of ascorbic and citric acids, and has a pH of roughly 2-3. You’ll see the same effect with vinegar too, although that mixture wouldn’t be quite so nice to drink. (If you’re feeling adventurous, try some common alkalis such as baking soda or bleach, but DEFINITELY don’t drink those concoctions afterwards…)

3. Carry out combustion.
Ever lit a match? Or a lighter? Started your gas cooker? Turned on your gas boiler? Started your petrol or diesel car? Of course you have. Every single time you do any of those things, the carbon atoms in their molecules are reacting with oxygen to produce carbon dioxide and water. And even if you live under a damp and fireless rock, you’re still doing it – respiration, the process by which all your cells obtain energy – is a form of combustion.

4. Watch some ice float.
Ice floats. Stop press!
We take that for granted, but it’s amazing really. This is a brilliant bit of chemistry that has its tendrils in physics and biology too. Solids don’t generally float on their liquids. Solids are usually more dense than their liquid form, so they sink. But if water behaved like that we wouldn’t have life on this planet, because every time any body of water got really cold it would freeze from the bottom up, taking out all the life swimming in its depths in the process. Since we’re fairly sure that life began in the oceans, evolution would have come to a full stop. But water doesn’t behave like that; water expands when it freezes. Why? Because water has something called hydrogen bonds between its molecules, and as it solidifies these bonds increasingly force the crystalline structure to be very ‘open’. As a result, ice is actually less dense than water, so it floats. This is also why ice is so brilliant at cooling liquids; the warm stuff rises, hits the cold ice and sinks again, creating a sort of cycle called a convection current. Who knew there was so much sciency stuff in your spritzer?

5. Bake a cake.
Food is a rich source of chemistry, just ask Heston. In this case, I’m thinking of baking soda, otherwise known as sodium hydrogencarbonate, or sodium bicarbonate (NaHCO3). When it’s heated above about 70 oC it undergoes a chemical reaction called decomposition. In other words, its molecules break apart without actually needing to react with any other substance. When you put baking soda into your recipe, or use ‘self-raising’ flour (which has it already added), you’re setting it up for this chemical reaction. As the cake cooks, the mixture heats up, and the baking soda does this:
2NaHCO3 –> CO2 + H2O + Na2CO3
The carbon dioxide, CO2, is a gas and it pushes your mixture up and out, causing it to rise. No baking soda chemistry, no lovely, fluffy cake.

So, next time someone tells you they’re rubbish at chemistry, you can point out that they’re doing it every day!