[redfox]

What technique is best to isolate pure samples of
i) Benzene (bp 80 degrees C) and 2,2-biphenyl (phenylbenzene, m.p 71 degrees C, b.p 256 degrees C)

ii) 2,2-biphenyl and benzoic acid (m.p 122 degrees C)

10g sample of the mixture in each case

I know that sodium carbonate could be used to extract ether solution after acidification and dissolution in ether. The base should convert the benzoic acid to salt. Afterwards dilute HCl can be added til the solution regenerates acidity, then the product may be recrystallised for a more pure substance.

I'm not sure what the method is to purify an organic compound by solvent extraction, or what methods to use to separate biphenyl, and benzene, as listed above. 10g is important to include...but I don't see how!

Thanks in advance for any advice offered:)

[Yggdrasil]

There is a very easy way to separate benzene and biphenyl based on a specific physical property (hint: the physical property is listed in the problem).