2,6-dimethylaniline was synthesized using the following procedure: Placed 22.557

Question

2,6-dimethylaniline was synthesized using the following procedure:

Placed 22.5575 g (approximately 0.10 mol) SnCl2 ? H2O into an Erlenmeyer flask. Dissolved the SnCl2 ? H2O by adding 40 ml of concentrated HCl to the Erlenmeyer flask and using a steam bath. Upon completion of the dissolution of SnCl2 ? H2O, a mixture of 4.5 ml (approximately 0.033 mol) of 2,6-dimethylnitrobenzene and 50 ml of glacial acetic acid were added to the Erlenmeyer flask. The resulting mixture was briefly swirled and then allowed to cool in an ice-water bath, producing a precipitate. The precipitate was collected via vacuum filtration.

The damp precipitate was put into an Erlenmeyer flask, to which 25 ml of water was added. To the Erlenmeyer flask, added 50 ml of 8M aqueous KOH. Allowed the mixture to cool to room temperature.

Extracted the aqueous mixture with 25 ml of diethyl ether, then extracted the aqueous mixture again with 10 ml of diethyl ether. Combined all ether extracts and washed with 2 x 10 ml portions of water, then dried over anhydrous K2CO3.

Decanted to remove the anhydrous K2CO3. Removed the ether by rotary evaporation.

Determined volume of 2,6-dimethylaniline and performed NMR spectroscopy.

2 ml of 2,6-dimethylaniline was obtained. I need to know the thereotical mass recovered and the % yield. Please show all work.

Explanation / Answer

Actually it's more easy than you think, because this is a 1:1 reaction ratio, and you also have the number of moles of the 2,6-dimethylnitrobencene. All you need now it's the density of the 2,6-dimethylaniline to convert the volume to mass and then compare that value to the obtained one like this:

moles of nitrobencene = moles of dimethylaniline

0.033 moles = 0.033 moles.

The molecular mass of dimethylaniline it's (according to Merck) = 121.2 g/mol

Theorical mass = 0.033x121.2 = 3.9996 g or 4 g if you want.

Now you obtained 2 mL, and the density of that compound is 0.98 g/mL so:

d = m/v m = d*v = 0.98 x 2 = 1.96 g that's the mass you obtained based on the volume.

The %yield = (1.96 / 3.9996) x 100 = 49.0049 %

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