The final product formed was characterized by using an infrared spectroscopy and chemical reaction. The IR spectrum was expected to show a carbon double bond (alkene) and many C-H sp³ hybridization bonds (alkyl) from the final product. This was compared to the authentic sample with its vibrational bonds. Once done identifying how close the sample is with the authentic sample, that would be the evidence to support the product’s
The purpose of this experiment was to identify one ketone with Thin Layer Chromatography and one using NMR spectrometry. We will do this by making 2, 4 a DNPH derivative and checking the melting points.
3. The IR spectrum of the starting material shows a medium/strong C-O bond at around 1500cm-1, also the starting material shows a strong C-H bond at around 3000cm-1 and another medium C-H bond at 2865cm-1 indicating an aldehyde group whereas the product does not. The IR spectrum of the product shows a two weak broad O-H peaks at around
An NMR spectrum was also taken for our product sample which was close to the ideal but was a little off. Ideally there should be five peaks for the five chemical shifts from the five hydrogen groups on the product structure. The first peak should occur in the mid six ppm and can be described as a quartet. The second peak should occur at a ppm in the high 6s and should be another quartet. The third peak should be a triplet occurring at a low 7ppm. The fourth peak should be close by to the third, being another triplet. Finally, the fifth peak should be a doublet occurring at a mid 7ppm. The ppms for the ideal and the actual differ greatly in the fact that they span from approximately 5.3-6.25 instead of the ideal 6.5-7.5. It is fact that chemical shifts caused by benzene rings occur in the 6 to 8 ppm range, thus the nmr we received as a result can be somewhat doubted.. Ideally the first and second peaks should be a result of the hydrogens furthest away from the rings and the
Determining the Molecular Formula of a Hydrated Copper (II) Sulfate Through the Concept of Moles
This could be improved by utilizing an inert atmosphere of solely nitrogen. Melting the compound resulted in an intensely dark purple liquid. This is a result of the resonance stabilized radical being formed by the homolysis of the carbon-to-carbon bond validating the photochromic properties. The colour change further substantiates that the desired product was produced despite the inaccuracies in melting point values. Homolytic cleavage of the dimer prepared by solvation with toluene results in a deep purple solution confirming the formation of the resonance stabilized radical.
Though the products had dissimilar melting point values, it is not enough to conclude that they are different. To be certain of the identity of the products, Infrared Spectroscopy (IR) and H- NMR were used. While IR is used to determine the functional groups present in an unknown substance through identification of covalent bonds, H-NMR is used to determine the structure of an unknown compound. The IR from both products had peaks at almost identical frequencies. The IR of both
The purpose of this experiment is to verify the formula of magnesium oxide based on the masses of magnesium and the product (MgO). We verify the formula firstly by calculating the empirical formula of magnesium oxide and then calculating creating the magnesium oxide itself- a magnesium ribbon is combined with oxygen in the presence of air through combustion and this forms MgO. The empirical formula of a compound is the simplest method of expressing a chemical formula in whole-number ratios of the constituent atoms that are consistent with masses measured in the experiment; whereas the molecular formula expresses the chemical formula using the actual number of atoms. For example, the molecular formula of anthracene is C14H10 while the empirical formula is C7H5.
Also, the similarity between the database reference of Isobutyl Acetate, reference IR data graph included, and the experimental IR would also suggest that the products are the same and suggest that the unknown reagent was Isobutyl Alcohol.
The powdered cobalt oxalate hydrate was weighed to about 0.3 g and placed in a pre-weighed crucible. The crucible and the cobalt oxalate were then heated until the cobalt oxalate decomposed into a stable, black solid, or Co3O4. Once the crucible was sufficiently
Experimental and Computation Vibration-Rotation Spectroscopy for Carbon Monoxide Through the Use of High-Resolution Infrared (IR) Spectra
The results from the NMR of 1-propanol showed 3 different prominent peaks with the peak at 2.2 cm-1 being the acetone. Because 1-bromopropane has three non-equivalent hydrogens it was found to represent this set of NMR data. The other product, 2-bromopropane only had 2 different types of hydrogens and would have only had 2 peaks. Further analysis of the structure of 1-bromopropane showed that the hydrogens closest the bromine group were an indication of peak A in the graph. Because of the electronegativity of the bromine, this peak was located further downfield. There were 2 neighboring hydrogens so using the n+1 rule gave the 3 peaks. Going down peak B showed the next carbon which had 5 neighboring hydrogens thus giving 6 peaks. Finally, the carbon furthest away from the bromine was found at peak C. It had 2 neighboring hydrogens and provided 3 peaks.
- The C-H bonds in this structure are shown at 1444 and 1368cm-1. These two bands indicate the two different types of C-H bends that occur on the molecule. One is that of the alkene and the other is that of the several alkanes on the molecule.
Through this experiment, I used IR and NMR to identify several unknown compounds. In order to identify my pure unknown compound, IR-12, I first looked for any medium to strong peaks on my IR spectra. The peaks that were useful in identifying my unknown were: a C-O bond of an ester at 1043.8, a C-O bond of an ester at 1243.6, a stretching C=O bond at 1743.2, a stretching alkyl C-H bond at 2860.4, and a stretching alkyl C-H bond at 2958.7. When figuring out which IR unknown was my compound, I first looked to see if my IR spectra showed an alcohol or an amine. Since my IR spectra didn’t show an alcohol or an amine, I was able narrow down my choices of possible compounds to twelve. Next, I looked for an aromatic ring in my IR spectra and since my IR didn’t show an aromatic ring, I was able to narrow down my choices to six possible compounds. Then I looked for any nitriles in my IR and since my IR didn’t contain any nitriles, I was able to narrow down my choice to five possible compounds. Then, I looked to see if my IR contained a ketone, an aldehyde, or an ester. My IR spectra didn’t contain a ketone or an aldehyde, however, it did contain an ester, which is how I was able to identify my unknown, IR-12.
There are four main regions of IR absorptions: region 4000 – 3000 cm-1 corresponds to N-H, C-H and O-H stretching, region 2250- 2100 cm-1 is triple-bond stretching , region 2000- 1500 cm-1 is double bonds and the region below 1500 cm-1 is the fingerprint region where a variety of single bonds are absorbed.3 The chromic acid test is a test for oxidizability and gives a positive result for primary and secondary alcohols as well as aldehydes2. A positive result in the chromic acid test is indicated by a color change and the formation of a precipitate. Tertiary alcohols give negative results for the chromic acid test since there must be a hydrogen present on the alcoholic carbon for oxidation to occur. The 2,4 DNP test, tests for a carbonyl and is therefore a dependable test for aldehydes and ketones. Finally, 13C NMR spectroscopy is a test to determine the structure of a compound. 13C NMR detects the 13C isotope of carbon. Each carbon has a different chemical shift. A carbon’s chemical shift is affected by the electronegativity of nearby atoms. Carbons that are bonded to highly electronegative atoms resonant downfield because the electronegative atom pulls electrons away from the nearby carbons and cause those carbons to resonant downfield1 (John McMurry, 2008). A general trend is that sp3-hybridized carbons absorb from 0 to 90 ppm, sp2-hybridized carbons resonant between 110