Question

In a Cannizzaro reaction (unknwon benzaldehyde with 4ml of 10M KOH and 5ml Methanol)

1. Prepare a flow chart of the procedure you plan to use to separate the two possible products from each other.

2. Calculate the amount of 6 M HCl that is needed to acidify your reaction mixture to pH 2 after the reaction is complete.

3. Prepare a flow chart to show how the reaction and isolation process will be conducted and to show the reactions that are occurring during the isolation process.

Answer 1

Canninzaro Reaction involves the bare incluced of two molecules of allehyde (which lacks to give a primary alcohol and a carboxylic Mechanim despropotion a bydrogen' acid. MINIJU N Bocedure weighed it in the amount of SmL of meon. ablehyee and dissolved stirred with glas rod. / Transferred IOM KOH the solution reflused the to RB containing trul of reaction nixture (supension) as solid starts Shaking is requied sticking the walls in between of RB. Cooled down the reaction mixture in ice both and separated the product. NOW this Product is the mixture of alcohol and acid separation is done to isolete bater the Prodeech. Se Extract the reaction mixture with diethyl ether. Added saturated solution of Natio o aqueous layer. Estracted thrice by abliding little amount of saturated Narco because he is Aqueous layer more dense is at bettem than ethol. pressure os co is libereted. vent off ecover the the alcohol by distilling out the eter

Recover the acid by aolding cance. He to the aqueous layer... Add volume ce depends upon the amount of benzoic acid Added till aqueous layer becomes acedie and cooled in ice bath product (acid) got separated out. Recrystallised both the alcohol and acid and verify by taking meeting panit bat Reactions involved + + NOHO AL-C-o-Nat (aa) + con + H2O aqueous layer HU A2-C-onat thot - A-COH (3) + H₂O (2) (separates out from aqueous solution)
the addition of hcl hcl actually depends on the amount of benzoic acid.

But here general calculation we can make for pH=2 we need 0.135 [H+]..it can be achieved by adding 22.5 ml of 6M Hcl