How do you convert ethanol into propene???Watch
Maybe oxidise the ethanol to ethanal (distil with acidic potassium dichromate)
React with methyl magnesium bromide (Grignard), acidic workup.
Dehydrate with conc. phosphoric acid at 350ºC
I have some propene and am willing to swap it for ethanol.
Mmmm, lovely yummy ethanol.
Failing that, and assuming it was an AQA student asking I'd HBr it, then H+/CN-, then acid hydrolysis of the nitrile, then LiAlH4, followed by dehydration.
Another way is dehydrate ethanol to make ethene, add HBr (electrophillic addition) to make bromoethane, add KCN to make propanenitrile via nucleophillic substitution, acid hydrolysis to make propanoic acid. Reduce this using LiAlH4 dissolved in dry ether to propan-1-ol, then dehydrate again to make propene.
You already have the standard A Level answer from Pigster.
A different option would be a Wittig reaction, where MePPh3+Br- is deprotonated by a strong base (say BuLi), forming an ylid, to which ethanal is added which you make by oxidising ethanol. This is arguably a better (and practically much quicker) method, but involves reactions you don't learn about at A Level.