Emulsions and there properties

[rae]

Morning,
Yr 12 Senior science prac looking at emulsions and trying to distinguish between oil based and water based.
Does any one have any tips on how to get this to work? You look at conductivity and the solubility of a water soluble dye and a oil soluble dye. We did it this morning and all our results were dubious!

Thanks
Lorrae

[RosalieM]

I don't really know what this prac is but colouring for chocolates is oil based so should be soluable in oil. I don't know if you can buy it at supermarkets or not. We used to make chocolates a lot as kids

[dime]

Last week I prepared a prac for Senior Science and it consisted of three green solutions in jars with lids so they could be shaken up. I don't have the book it came from, so I'm not sure what they were testing them for. All I know they had to look the same, so they were: Nickel Chloride a bit stronger than 0.1M, some green powdered chalk in water, (used regular chalk not the dustless stuff) and a mixture of some vegetable oil, green detergent and water. They all looked similar shade of green and they were labelled A B & C. I guess they shook them and observed them.

They also made french dressing, and mayonnaise - with egg, for emulsions. I imagine these pracs are in the Heineman Senior Science @ HSC book.

[rae]

Yes we did that prac as well. This is the next one and it is a dot pint so they have to do it. Just was looking for some pointers to make ot more successful!

[dime]

Just re read your first post, and while I haven't got the info on conductivity, Sudan III is an oil based dye isn't it.