Chem

Purpose:

The purpose of this experiment is to synthesize 11.0 mmol of n-propyl propionate (n-propyl propanoate) from 1-propanol and propanoic acid. The presence of an ester in the products will be confirmed using infrared spectroscopy.

Reaction Scheme:

Experimental Procedure:

To a 5 mL round bottom flask was added 1-propanol (0.823 mL, 0.011 mol), propanoic acid (0.973 mL, 0.013 mol), concentrated sulfuric acid (2 drops), and boiling chips (~3). The flask was then swirled and attached to the refluxing apparatus. The solution was refluxed for 45 minutes, adding the organic layer collecting in the side-arm back to the flask every 15 minutes. The solution was then extracted with water (1 mL), saturated aqueous sodium bicarbonate (1 mL), and saturated aqueous sodium chloride (1 mL) in a centrifuge tube, removing the aqueous layer after each extraction. To a vial was added the organic layer and anhydrous calcium chloride spheres (~5). The vial was swirled until the spheres no longer clumped together and was then let sit for 5 minutes. To a clean, dry, tared 5 mL round bottom flask was added the liquid from the vial. After the solution was weighed, the flask was attached to the distillation apparatus and product was collected at 109 ± 2 °C. The solution was then weighed again and an infrared spectrum of the product was obtained.

Results:

Empty round bottom flask = 5.396 g

Empty 50 mL beaker = 28.923 g

After reflux:

Crude product (with flask/beaker) = 34.922 g

Crude product = 34.922 – (5.396 + 28.923) = 0.603 g

Empty product vial = 17.731 g

Actual BP of n-propyl propionate = 122-124 °C

Product collected from 100-109 ± 2 °C

Plateau at 109 ± 2 °C = BP of product

After distillation:

Distilled product (with vial) = 17.837 g

Distilled product = 17.837 – 17.731 = 0.106 g

Theoretical yield:

11.0 mmol 1-propanol 1 mol 1-propanol = 0.011 mol 1-propanol

1000 mmol 1-propanol

From balanced equation:

1...