I have a 2 part question here. First of all we added 1cm^3 light petrolium to 3 test tubes. Then we added 1cm^3 of aqueous chlorine, bromine and iodine solution to each tube respectivly. Then we shake the test tubes to mix the solution. This ended up in the solutions seperating into layers. No prob.

 

The questions are What is light petroleum, and I assume they seperate into layers due to the different denisty. Which is at the top? Has light petoleum got a greater denity than Cl2(aq), Br2(aq) and I2(aq) ?

for a start Liquid Cl2 in a test tube would Some achievement in itself!

 

as for Light Petroleum, it`s not Really a definition, what I will say is that it will be straight chain Alkane with about 6 to 8 carbons in it. it`s a Very Fuzzy question!

No its was Dilute Cl2. Sorry. Cl2 solution. Ok. thanks anyway. I understadn the principle of it now so its cool.

The halogens dissolve more easily in the alkane mix than in water. So, you extract them from water and they go into the alkane mix.

 

The solutions only are dilute, so the density will hardly be affected by the presence of the halogen. The alkane mix has lower density than water and the layer on top is the alkane mix, with the halogen dissolved in it.

 

Iodine also dissolves with a different color in the alkane mix, it is purple, while in aqueous solution it is brown. (Btw, iodine only dissolves VERY sparingly in water, when some iodide is added, it dissolves more easily.)

Thank you very much for your help.