Benzene Synthesis

In this video, benzene is synthesized from the dry distillation of 81.9 grams of sodium hydroxide and 268.1 grams of sodium benzoate, both commonly available consumer products. It is then distilled, and dried before storage.

Though an extremely useful chemical in organic synthesis, benzene is a proven carcinogen and any exposure to it should be as limited as possible. Benzene is also easily flammable and proper precautions must be taken to prevent accidental ignition.

Category:

Science & Technology

Tags:

• Benzene
• synthesis
• distillation
• how
• to
• make
• chemistry
• C6H6
• production
• dry
• sodium
• hydroxide
• benzoate
• biphenyl
• NaC6H5COO
• NaOH
• benzoic
• aromatic
• chemical
• benzol
• cool

[daviddanielgraham]

Hi, nice video, and cool apparatus for the first distillation. Propane and melting point of 600 degrees are a good heating choice - well chosen with the camp stove. Can you please describe what is happening chemically? The sodium / calcium hydroxide is releasing hydroxide ions, what is the Sodium Benzoate's role in the transaction? Could Potassium Benzoate be used as well? Thanks 1x10E6!!! (A million!) and very interesting stuff. :)

[ReactionFactory]

@daviddanielgraham

If I'm not mistaken, neutral carbon dioxide comes off anionic benzoate leaving a phenyl carbanion which then nucleophilically abstracts a proton from hydroxide to produce benzene distilling off. The remaining sodium oxide then reacts with the carbon dioxide produced earlier to form sodium carbonate which remains in the boiling flask.

Potassium benzoate is suitable as well, so long as you change the recipe so as to keep the molar ratios the same.

[chemC2H5OH]

Very nice video ! Be extremely careful with benzene. I think this red material in the flask is from various polycondensation of benzene, like tetracene (red-orange color), equation :

4 C6H6 => 3 C2H4 + C18H12

[ReactionFactory]

@chemC2H5OH

We think something like fluorene or fluorenone is present, as it fluoresces under a black light. I've read papers describing the pyrolysis of benzoate salts which indicated that possibility.

[superawesome484]

do you have to have copper pipe?

[ReactionFactory]

@superawesome484

Most metal pipes should be fine if you have a good seal, they don't melt, and don't react. What are you thinking of using?

[risbolla]

Everyone loves ⏣

[MrDaim1993]

this method is as same as preparation of methane where we add sodium acelate (CH3COONa) with soda lime (NaOH + CaO) to give methane (CH4) and sodium carbonate (Na2CO3)

[AngryPigFetus]

Dumb question but how much Benzene did you get out of this synthesis?

[Revelde20]

@196Stefan2 thank you !

[196Stefan2]

@Revelde20

I am afraid no: Cinnamon only contains small amounts of Cinnamaldehyde and Cinnamic acid, which also would lead to adverse side reactions. Sodiumbenzoate is the best starter material for the preparation of Benzene, only a decorboxylation step has to be carried out (apart from refining the raw benzene by a repeated distillation).

[196Stefan2]

If you want to re-use your "dry distillation apparatus", you could improve your device, when you'd replace the Mighty Putty "gasket" by a thread cut in the copper pipe, together with a nut and a flat gasket at each side of the tin's lid. Times have changed: When I was young and made chemical experiments (in 1976 I was 14), Benzene was sold at each pharmacy or drug store without restrictions at any hobby-chemist.

[Revelde20]

can benzene be sinthesice from say cinnamon?