Question

1. On development of the TLC plates for ortho- and para-nitroaniline, which isomer travelled faster? Why? What was the solvent? What is the thin layer made of? (4 pts) 2. 1.000 grams of acetone was reacted with 3.651 grams of benzaldehyde in a mixture of water and ethanol and an excess NaOH. The isolated dibenzalacetone product was 2.015 grams. What was the limiting factor? What is the structural formula of the product? What was the yield as percent of theoretical? C = 12.01 amu, H = 1.008 amu, 0 - 16.00 amu. (4 pts) 3. Outline the mechanism of the reaction used to prepare dibenzalacetone. (4 pts)

Answer 1

ANO or the nitrooniline NO P-nitro aniline Since ortho Nitro aniline involves intramolecular hydrogen bonding therefore it is less polar as Compare to þ-nibobbend. Ortho Mibo bhenol will bravel Faster Than benito Thin Layer is made up Silica (SO) Phenola H-- to Lintramolecular H bon I in ortho nitrophenol =(# - - 1g Acetone dibenzal acetone 3.6519 (Benzaldehyde) dehyde (200159) No. f Moles J Acetone --Has Moleculer Mass No f Moles of Benzaldehyde- Mass 58 0.0172 – 3.651 -0.0344 Molealer Man 106 So No of Moles of Acetone Therefore Acelone are less than benzaldehyde, is limiting factor.

I Mole will Acelone will give I Mole of dibenzal acelone 589 f Acelone will give 234g of dibenzal acetone lg g Acetone - 234 g of dibenzalachane lg g Acetone - 4.084g of dibemal actone Yidd oltained 2.0519 2.051 -xloo - 50.84% 4.034 9999 PPP fe C-CH p=com_ -Ho -CH=CH - C - CH = CH -