Ionic bonds practical demonstration

[Stevie D]

Hi folks,

 

I finished an Environmental Science degree in the summer of last year. I've since started a post-grad certificate which will enable me to teach. In my placement, I am currently teaching biology, chemistry and some maths bits and bobs the details of which aren't relevant here.

 

I am going to introduce ionic bonds in a few weeks' time. I like to throw in plenty of practical work, because, well, best way to keep people engaged innit.

 

So my initial thought was to do an electrolysis experiment. Graphite electrodes in a copper sulphate solution, that sort of thing.

 

That said, the risk assessment / health and safety side of things could get messy, what with the copper sulphate toxicity and even a mild build up of sulphuric acid in the solution as the result of the reaction. The theory is a bit busy, too, given my (adult) learners' current level of understanding.

 

So I'd rather keep it simple.

 

I've been reading Raffan, J. and Ratcliff, B. (1995) Foundation Chemistry. Cambridge: University Press.

 

On page 33 is a tidy little demonstration of ionic separation. I've attached a crude photo of the diagram to this post.

 

I would like a cheap and cheerful practical demo, lasting no more than 30 minutes, where an ionic compound can be easily spread over a porous piece of card, like in the photo.

 

My questions to you are:

 

What type of card would you recommend, and what dimensions?

What type of ionic compound, and how much?

What voltage should be applied across the electrodes?

 

Thanks for your time,

 

Steve

[studiot]

This might give you some ideas

 

https://www.google.co.uk/#q=electrophoresis

[Enthalpy]

Copper sulphate is used in multi-kilogram amounts on trees. I wouldn't worry too much. About the acid neither.