[ILoveISO]

"Give both theoretical and experimental melting points of my product. Compare and comment on the purity?

Theoretical was 92 - 92.5 degrees while my experimental was 92 - 95 does this mean that my product isn't that pure? anyone know? Thanks

[BetaAmyloid]

Well, you had about a 1-3% error yield on melting point. So, that isn't that bad, this may not be just due to your substance, it couuld be mechanical error - such as the instruments used. But, I wouldn't know exactly what substance is mixed with your product substance, but it would obviously be one with a higher melting point.

If you know what you were mixing together, you could look on the internet to which has a higher melting point, then hypothesize that whatever product has a high-high melting point is still somewhat present in your product.

[ILoveISO]

It was dissolved aluminum foil which turned into white powdery stuff and I put a bit of it into a small testtube and burnt that

[BetaAmyloid]

I still don't know what the experiment was. 

You gotta tell us exactly what was mixed/used/done.

[ILoveISO]

The experiment is called "The synthesis of potassium alum by recycling aluminum"

Basically I took ~1g of aluminum foil, ripped it into little pieces and put it into a beaker with 1.4M of potassium hydroxide. This was then heated up till it started to boil then was cooled in a ice bath. I then added 9M of sulphuric acid and dissolved the remains inside and reheated everything till it all dissolved then put into a ice bath and made the stuff crystallize. Once it was powdery I took a sample of that in a beaker and put it over a flame and viewed the thermometer in it to see when it boiled at what degrees