[Mark S 2014]

In my first lab session I carried out a simple and fractional distillation. The temperature in the simple distillation stabilises at around 77-79 °C. There are several organic compounds that this unknown liquid could be, I need to make an assumption based on the boiling point. Out of the compounds I have been given to choose from the most realistic option is cyclohexane which has a boiling point of 80.7°C, the next closest being hexane at 69°C. Is it reasonable that it could be cyclohexane even though the its 4°C short of the boiling point ? I can't see it being cyclohexane as the difference is too large.

[Hunter2]

What about Ethanol.

[DrCMS]

Ethyl acetate also fits but I guess this is a practical lab experiment in which Mark S 2014 was given an "unknown" sample and a list of possible components and it's his job to determine which component(s) was in the "unknown" sample.  If ethanol or ethyl acetate are on his list they are a better match but if the only choices in that range are hexane or cyclohexane.  Its most likely cyclohexane and his measurements are a bit off.

[Corribus]

What's you're elevation, Mark S 2014? Most literature boiling points are reported at sea level. If you're doing this experiment in Denver or something, that could be a source of your deviation. (Water boils at about 95 °C in Denver, 5 °C lower than the reported value of 100 °C.)

[Mark S 2014]

Well i'm doing this in England so i'm not too sure about the sea level thing ! Basically, only cyclohexane and hexane fit the bill at all, others had BP over 100°C. The first drop appeared at around 75°C... Maybe there was inaccuracies in the thermometer because I don't think I would be up to 4°C out on the readings. This was my first lab session and I'm really not happy that my results appear to be off.

[Mark S 2014]

Choices where:

1-octene
azobenzene
cyclohexane
cyclohexene
hexane
octane