Teaching optical isomers

I've just started to teach this topic to my students. It doesn't take too long but I do find it an enjoyable topic to teach. But how do you teach it? I always warn the students that the topic is jargon heavy - the words / phrases used in the topic such as  chiral, racemic, racemate, optically active are all pretty specific to optical isomers and are not used outside of the topic. In my teaching I have found that students understand the ...

Optical isomerism

Optical isomers are hard to conceptualise. They are molecules with the same molecular formula and structural formula. They look exactly the same both on paper and in the real world. However, they only exist in pairs, it is only possible to get two optical isomers of the same molecule which makes things a bit easier to deal with (it should be notes that a molecule such as C5H12 has three isomers - not optical isomers but structural isomers, namely pentane, 2 methylbutane ...

Synthesis of Aspirin

Aspirin has been with us for long time - the first documented reports of its use occurred over 2000 years ago. That said, the aspirin may not be in the form that you instantly think of (ie, a tablet) but it has been used all the same. Aspirin is an analgesic, which means it has pain killing effects and it has been well documented that the ancient Egyptians used a special tea made out of willow bark to treat a number ...

Practical application of the ideal gas equation

How many moles of air are in your lab? What mass is this air? These are a couple of great questions you can set your students and ask them to come up with some answers using the ideal gas equation. You will need a barometer (to determine the air pressure), a thermometer (to determine the temperature of the lab) and a rule to calculate the volume of the lab and hopefully some imaginative students. I carried out this work with my class a while ...

Carrying out a good IA project

Have you stated your Internal Assessment(IA) yet? If you are a 'May session' school, this anytime from May of IB1 until December of IB2 seems a likely time that your school will carry this out with you and ask you to write it up. Which means that you need to get some ideas on what types of things you can investigate. However, the aim of this blog post is to give you some ideas for writing and carrying out a good ...

Good Practice – Carrying out a lab

Here is an idea I got from a colleague of mine recently for a novel way of getting your students to plan a lab investigation. It is a model that could be rolled back and used in a variety of labs and it is very straightforward to do. Essentially, you give the students a task (for example, testing for halides) and then give the students a framework in which they can plan their own personal investigation. For example, you give them ...

VX – What is it?

Over this last month or so, the nerve agent VX has hit the headlines for all the wrong reasons but I did think it was worth looking at the chemistry of this molecule in this moths blog post. The obvious question is what is it? VX, or, to use the full IUPAC name is actually Ethyl ({2-ethyl}sulfanyl)(methyl)phosphinate. It is referred to as VX as it is a ‘V’ series of nerve agents (‘V’ stands for venom) and was first syntheiszed in the ...

Man Made Minerals

This blog post was inspired by a recent BBC article I read on minerals. The full article can be found here if you would like to read more (after you have read this blog post, of course!): http://www.bbc.co.uk/news/science-environment-39133897 It has recently been announced that over 200 ‘new’ minerals (4% of the total known minerals) have been discovered – these minerals own their existence to us. As strange as it sounds, human behaviour has led to the formation of these substances. To me, ...

Metallic Hydrogen and Scepticism

Scientists are supposed to be sceptical of others claims – you will encounter this in NOS (NOS 1.7 ‘Scientists must adopt a sceptical attitude to claims’). Why do I quote this? Well, you may have recently read or seen in the news that a new form (state) of Hydrogen has been produced. Hydrogen has been subjected to incredibly high pressure (495GPa or 495,000,000,000Pa – that’s 495 billion Pa). By contrast, standard atmospheric pressure is around 100,000Pa so this value is getting ...

Teaching Born Haber Cycles

I must admit, this is not my favourite topic to teach but it’s something I am working at. What I want to focus on here is not necessarily the cycle – I’m assuming you are OK with this. I’d rather focus this blog post on two other trends that can be identified using the data book: How lattice enthalpies vary according to: Size of the ion Charge of the ion I will also be referring to table 18 of the data book, ...