Cryolite – Everything you wanted to know and more

It happens every year doesn't it? You are teaching about the production of aluminium, you say that cryolite is used to lower the melting point* and some bright spark starts asking you about cryolite. What is it? Where is it from?  and so on. Well todays positng is aimed at keeping that inquisitive student quiet. All his or her questions can now be answered. Read on.... ..... Cryolite is sodium aluminium fluoride (NaAlF6) and is actually a synthetic substance. In the Hall - ...

Why does it smell so bad?

This is not directly IB related but it is certainly Chemistry related. I was carrying out the reaction between iron filings and hydrochloric acid yesterday. An experiment I am sure many others out there have carried out. The context is the reactivity series and it also involved reacting magnesium, aluminium, copper and zinc with hydrochloric acid. I have carried out these reactions many times in many different schools and continents and always get the same puzzling result. The iron reacts (fine) butr ...

Bullet ptoof sapphire

Aluminium oxynitride (AION) - marketed under the name ALON. The material is 85% as strong as sapphire, is a ceramic and has similar structural and optical properties to sapphire. Image kindly reproduced according to the licence at:http://en.wikipedia.org/wiki/File:Star-Saphire.jpg Research has shown that it is able to withstand armour piercing rounds fired from Russian and Browning sniper rifles. It is stronger and more lightweight than existing bullet proof glass. Its strength lies in its structure. Regular bullet proff glass is from layers of laminated glass and ...

Toxic Sludge

  What have Iron Oxide, Aluminium Oxide, Silicon Dioxide, Titanium Dioxide and Sodium Oxide all got in common? Well, they were the substances found in the highest concentrations in the recent toxic sludge spill in Hungary. What effect will they have? It seems open to debate at ther moment but you can read more here: http://www.bbc.co.uk/news/world-europe-11492387

Old pesticides

  We have carpet moths! Our carpets are apparently good quality and have natural fibres and this has attracted the moths :cry: It's not a huge problem but we have had to get the pest control guys around to fumigate the house. My wife was concerned about the chemicals that were being used but after a long chat with the guys involved we were happy with what they were telling us. Essentially .... ..... the EU tightly regulates this industry and the older, ...

Gemstones

  Gemstones are all broadly fromed in the same way - a liquid containing dissolved chemicals cools and crystals grow! However, the devil is in the detail..... ....Firstly, extreme pressure is also needed. Gemstones are rare becuae the correct chemicals need to be present in large enough quantities. Rubies and sapphires are essentially made from aluminium oxide. The red colour of ruby comes from traces of chromium. Sapphires colour comes from other elements, for example titanium or iron. Both rubies and sapphires also contain some magnesium ...

Solid – Solid Phase Reactions

  Most of the reactions we carry out in the lab involve a liquid reacting with another liquid, a liquid reacting with a solid or a solid reacting with a gas. There are no solid - solid reactions. Why? (You can post your reasons below) - if you cannot think of any please contact me!   The following clip shows that solid - solid reactions do occur and they can be quite vigorous! The reaction of Iodine and Aluminium N5h5ohd8298 Can you think of any reasons ...