Recent Posts by David Allen

Gar Jar Demos

I’ve recently been doing some demos showing how the pH of the period 3 oxides changes. The demos involved the combustion of various period 3 elements with oxygen, dissolving the oxide in water and adding universal indicator to show the pH. It’s very visual and always goes down well with the students. This made me think about all the different experiments I do using gas jars and the fume cupboard and I thought I would list them. I generally demo sodium, ...

Ethanedioic Acid Titrations

It's that time of year where if you are in IB1 you may well be starting to think about your IA. What will you do?! I hope today's post gives you some ideas. Have you thought about working with Ethanedioic acid (HOOCCOOH) or oxalic acid to give you its more common name? Ethanedioic acid occurs as a free acid in beetroot leaves and rhubarb. Could you extract it and see how much you have? You could titrate it with a base, such ...

SN1 vs SN2

I have not long been back from Oxford in the UK where I was running a revision course for OSC. One of the concepts that the students seemed needing clarifying was when to decide when an organic reaction was SN1 or SN2 so I thought it may be worth sharing this with you in this blog post: First of all, some definitions. S = Substitution (there are other types of mechanisms out there such as elimination and addition.) N = Nucleophilic (it is ...

Inquiry-based Learning

The MYP is all about inquiry-based learning but how much of it goes on in your diploma chemistry. 'I don't have enough time' is a commonly heard sentence in workshops. 'I can only just cover the content in the time I had, let alone fit in something extra'. Well, if you do it right, inquiry-based learning it should help you to gain a bit of time. First of all, I am sure many readers teach DP chemistry but not necessarily MYP science, so what ...

Concept-based Learning (CBL)

CBL or concept-based learning is (and has been) a real buzz word in IB circles. But what is concept-based learning and how can you bring it into the classroom? I am hoping that this month’s blog post will give you some ideas that will motivate you to find out more about CBL and hopefully, try it out in class. CBL is driven by ‘big ideas’, rather than content that is subject specific. CBL also supports the attributes of the learner profile. ...

Redox Cells: Revision Checklist

When I teach about redox cells, I like starting with the Daniell cell. It is an example of the world’s first battery (cell) and if you remember the details of it, you can apply to same rules to any unfamiliar redox cells. First, a diagram of the cell itself: Hazmat2, via Wikimedia Commons (CC BY 3.0) Note that the zinc half cell is on the left and the copper half-cell on the right. This is important to remember when it comes to ...

Global Warming

Global warming is still a topic that stirs a range of emotions in people. Is it real? Is it made up? Is it something to worry about or not? Will it actually affect you? But, love it or hate it, the topic is not going to go away. We have just had some training on how to teach this and I thought it was worth sharing with you. Take the premise 'Global Warming is going to cause more extreme weather patterns'. Then, think of the ...

Visible Thinking Routines

We have just had some great INSET on 'Visible Thinking Routines'.  To be honest, I thought this was going to be some complicated and difficult 'new' way of teaching things (apologies for my skepticism) but as the session went on I came to realize that yes, it was something new for me to think about and do but it wasn't at all complicated. In fact, many of the ideas used I already use myself anyway: the INSET session just helped me ...

Differentiating Your Lessons

When I started teaching (22 years ago) differentiation was the buzz word. We had extensive lectures on it in my teacher training qualification, and the schools I carried out my teaching practice in were ensuring that all of their lessons were ‘fully differentiated’. Invariably, this meant having three worksheets up your sleeve, an easy, medium, and difficult one. You would then give students a worksheet according to their ability (this was labelled differentiation by task). There was also differentiation by outcome, where ...

Acid Deposition

The topic of acid deposition can be found in the SL section of the acids and bases unit, section 8.5. As a teacher, when I first read this title I had no idea what it meant, but, as with most things in the IB, the title is actually quite descriptive, once you know what the title means. The key word is ‘deposition’. It means (according to the definition in the online dictionary by Merriam-Webster), simply, ‘the act of being deposited’.1 So acid deposition ...