Dead Arty – Beautiful Science

I made this video for a short film festival. These are some colourful highlights from some of our science experiments.

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Sodium bicarbonate and sodium citrate

zeplora fizzy tablets citric acid IMG_4936

Since baking soda and citric acid in water make a good fizzy reaction, I thought it would be interesting to make tablets of each, to add to water.

I recently figured out how to make baking soda tablets, and was able to use the same method to make citric acid tablets. The tablets contain citric acid and gelatine powder in equal quantities, with a few drops of food colouring.

Mixing
Mixing
zeplora fizzy tablets measuring IMG_4935
Measuring the amount per tablet
The plastic insert in the garlic press.
The plastic insert in the garlic press.
Mixture in press, about to be compacted
Mixture in press, about to be compacted
The two types of tablet, ready to go
The two types of tablet, ready to go

The reaction when added to water seemed slower than just the ingredients alone, probably because of the gelatine.

Here is the reaction formula:

3NaHCO3 + C6H8O7 → 3Na+ + C6H5O73- + 3H2O + 3CO2

The gas is the CO2.

After about 1/4 of an hour the mixture looked like this:

The result after letting the mixture sit for about 1/4 hour.
The result after letting the mixture sit for about 1/4 hour.

Simple home made magnetic stirrer

This is a really simple magnetic stirrer. All it has is two AA batteries and a 12 V computer fan with a neodymium magnet on top of it. Then a ‘flea’ (a magnetic stirrer bar) goes in the beaker and you put the stirrer underneath and it stirs the mixture. So simple!

You can use any kind of motor, it just shouldn’t spin too fast. A computer fan was the most reliable kind of motor we had available at the time. The magnetic field has to be side on to get the flea to spin (see diagram further down). The magnet was round and had to sit on its edge, so we added a couple of pieces of wood to support it.

We used a retort stand to hold a flask of mixture just above the magnet.

Fan with neodymium magnet and wood, connected to two AA batteries
Fan, with neodymium magnet and wood, connected to two AA batteries
[vimeo https://vimeo.com/122868476]

This would have been NZ$160 if we had bought it!!! It was probably under NZ$10 to make!!

Diagram of setup (not to scale)
Diagram of setup (not to scale)

This was mixed with the magnetic stirrer and left to form the copper sulphate crystals (CuSO4):

zeplora copper sulphate IMG_4653