9 Layer Density Tower

There's also the simple version from STEM York. Equal parts propan -2 -ol and concentrated NaCl solution in a small, screw-top bottle. Add about 20 each pieces of chopped up plastic milk bottle cap and plastic fork tines. Shake it up and leave it. The two plastics will separate, one to the top and one to the bottom. As everything sorts itself out, they all gradually converge on the boundary between the two liquids. It will start off a bit foggy but gradually clear over a few weeks.
 
What could I use instead of rubbing alcohol?

Any kind of ethanol contaminated slightly with food colouring will do the job?
 
What could I use instead of rubbing alcohol?

Any kind of ethanol contaminated slightly with food colouring will do the job?
Any variation will have a slightly different density, so the only thing you can do really is to experiment with what you have.
Try a small beaker with 2 or 3 different liquids at a time, until you know the order of their densities.
 
Any variation will have a slightly different density, so the only thing you can do really is to experiment with what you have.
Try a small beaker with 2 or 3 different liquids at a time, until you know the order of their densities.
Well I can't purchase lamp oil so my top layer will be the alcohol and then the vegetable oil,

So I believe they are definitely going to distinguish as layers but of course I will first try it,

Would you suggest olive or other plant oil?
 
A safer version is using sugar solutions of diffrerent densities, each coloured differently. With reference to the quoted websites and worksheets the chemical names and ranges are American in origin and some don't totally translate across.
 
Well I can't purchase lamp oil so my top layer will be the alcohol and then the vegetable oil,

So I believe they are definitely going to distinguish as layers but of course I will first try it,

Would you suggest olive or other plant oil?
lamp oil = kerosene like in paraffin spirit burners,
 
Well I can't purchase lamp oil so my top layer will be the alcohol and then the vegetable oil,

So I believe they are definitely going to distinguish as layers but of course I will first try it,

Would you suggest olive or other plant oil?
Even different vegetable oils will have different densities, so sunflower and olive would probably create different layers.
I have found that even different brands of hand and dish soaps work.
Different syrups & honeys work too, like Golden syrup, maple syrup, clear honey, set honey and treacle.

Some of these will mix over time but should be fine for a week or two.

As I said, just get lots of different things and try them out, I have to try different things each year as I run out of previous supplies or brands.
 
Hi
I did something similar, but with sugar solutions instead:
If you've got more colours you can do more layers :)
Density Rainbow Using Sugar solutions

Equipment:

  • Sugar
  • Hot water
  • Food colouring
  • Test tubes
  • Pipettes
  • Measuring cylinders
Method:

Either prepare sugar solutions in advance or allow pupils to make.

To make sugar solutions:

Add 2 dessert spoons of sugar to 200cm3 of hot water and stir thoroughly. Label this “2”. Colour this yellow.

Add 4 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “4”. Colour this blue

Add 6 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “6”. Colour this red.

Add 8 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “8”. Colour this green.
 
Hi
I did something similar, but with sugar solutions instead:
If you've got more colours you can do more layers :)
Density Rainbow Using Sugar solutions

Equipment:

  • Sugar
  • Hot water
  • Food colouring
  • Test tubes
  • Pipettes
  • Measuring cylinders
Method:

Either prepare sugar solutions in advance or allow pupils to make.

To make sugar solutions:

Add 2 dessert spoons of sugar to 200cm3 of hot water and stir thoroughly. Label this “2”. Colour this yellow.

Add 4 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “4”. Colour this blue

Add 6 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “6”. Colour this red.

Add 8 dessert spoons of sugar 200cm3 of hot water and stir thoroughly. Label this “8”. Colour this green.
We do something similar but double the quantities so that '8' resembles molasses or syrup
 
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