CRSEXP026

=Scheme= No Product [|Reaction Attempts] Chemspider: [|Acetone] + [|Propanoic Acid] =Researcher= Kayla Gogarty =Objective= To observe the reaction of mixing acetone and propanoic acid at standard temperature and pressure by HNMR spectroscopy with D2O used as the external reference in the outer coaxial NMR tube. =Procedure= Four mixtures of acetone and propanoic acid were prepared. These four mixtures included pure reagent grade acetone, pure propanoic acid, a drop of acetone in an excess of propanoic acid, and a drop of propanoic acid in an excess of acetone. One week later, HNMR spectra were taken of the two pure mixtures. The mixtures were pipetted into an NMR tube with deuterated water in an outer coaxial NMR tube. One week later, a mixture of a 1:1 ratio by volume of acetone and propanoic acid was prepared. HNMR spectra were taken of the three mixtures, including a mixture with a drop of acetone in an excess of propanoic acid, a mixture with a drop of propanoic acid in an excess of acetone, and a mixture of a 1:1 ratio by volume of acetone and propanoic acid. =Results= [|HNMR Spectrum of Acetone] 1 week after preparing mixture [|HNMR Spectrum of Propanoic Acid] 1 week after preparing mixture [|HNMR Spectrum of Approximately Equal Amounts of Acetone and Propanoic Acid (by volume)] 0 hours after preparing mixture [|HNMR Spectrum of One drop of Acetone and an excess of Propanoic Acid] 2 weeks after preparing mixture [|HNMR Spectrum of One drop of Propanoic Acid and an excess of Acetone] 2 weeks after preparing mixture [|Calculated Mole Fractions Based on HNMR]

No new peaks were present. Therefore, no product formed. The acetone peak shifted in the presence of different mole fractions of propanoic acid. =Discussion=
 * [The singlet at 4.0 ppm from the acetone bottle is most likely consistent with about 5% impurity of water - see explanation This might also explain the shape of the D2O/HDO reference but not the large shift JCB]**

No product was formed by the reaction of acetone and propanoic acid. However, obvious shifts in the acetone peak were observed, depending on the mole fraction of propanoic acid. The peak for pure acetone was observed at 3.1ppm. The peak for acetone in a 50/50 by volume mixture of acetone and propanoic acid was observed at 2.85ppm. The peak for acetone of one drop of acetone in excess propanoic acid was observed at 2.655ppm. The peak for acetone of one drop of propanoic acid in excess acetone was observed at 3.075ppm. Therefore, propanoic acid shifts the acetone peak upfield and the higher the mole fraction of propanoic acid, the more upfield the peak shifts.

The expected acetone peak is at 2.05. However, the peak was observed closer to 3.0. The reason for this shift is unknown.

The peaks for propanoic acid also shift upfield in the presence of acetone. For example, the carboxylic acid peak for pure propanoic acid, 50/50 by volume acetone/propanoic acid, and one drop acetone in excess propanoic acid are 12.4ppm, 11.35ppm, and 12.25ppm, respectively. A carboxylic acid peak was not observed for one drop propanoic acid in excess acetone because the mole fraction was too small. =Conclusion= The mixture of propanoic acid and acetone did not produce any product after one week at room temperature. Propanoic acid shifts the acetone peak upfield and the higher the mole fraction of propanoic acid, the more upfield the peak shifts. Acetone shifts the propanoic acid peak upfield. Also, the reason for the acetone peak being observed at 3.0, instead of 2.05 is unknown. =Log=

2013-09-26
10:45-0.6600g of acetone were added to a 5 dram vial 10:45-0.8091g of propanoic acid were added to a 5 dram vial 10:47-0.0102g of acetone and 0.8270g of propanoic acid were added to a 0.5 dram screwcap vial 10:48-0.8502g of acetone and 0.0588g of propanoic acid were added to a 0.5 dram screwcap vial

2013-10-3
12:45-Propanoic Acid sample scanned in NMR at 25.0C Scan Parameters: 8 scans, 1s relaxation delay, 45degree pulse angle 12:50-Acetone sample scanned in NMR at 25.0C Scan Parameters: 8 scans, 1s relaxation delay, 45degree pulse angle

2013-10-9
11:15-0.4156g of acetone and 0.6040g of propanoic acid were added to a 0.5 dram screwcap vial 11:30-One drop of Acetone and an excess of Propanoic Acid sample scanned in NMR at 25.0C Scan Parameters: 8 scans, 1s relaxation delay, 45degree pulse angle 11:40-One drop of Propanoic Acid and an excess of Acetone sample scanned in NMR at 25.0C Scan Parameters: 8 scans, 1s relaxation delay, 45degree pulse angle 12:15-A 1:1 ratio by volume of acetone and propanoic acid sample scanned in NMR at 25.0C Scan Parameters: 8 scans, 1s relaxation delay, 45degree pulse angle