[Jzalkm]

hi,
I am trying to understand and write a report on a practical about the activation energy of acetone-iodine reaction. Without a good overall picture, it is often not possible to identify the source of problems which another chemist can easily pin-point. Hence, I will try to discuss and jot down the misconceptions, problems and thoughts I face on the way, if it is possible. Any help or positive critics in answering the querries, even if they may at times seem pointless, would be greatly appreciated.

Info on lab:
Titration method using thiosulfate has been used to follow the rate of reaction . The experiment was carried out at different temperatures for fixed initial concentrations of propanone, iodine and H+. (assumed reader is familiar with this rate reaction). The orders of the reactants were not determined in this experiment.

querry 1: is it right if we use density to determine concentration of 10ml acetone?
querry 2: Is it possible to double the concentration of propanone?  (I am currently of the opinion that propane is a liquid and it has a fixed concentration- so it will be a bit like doubling concentration of water which is not possible). my answer would be no, true? To lower its concentration i would consider adding water, true?

Best Regards,
Jalal