The purpose of this lab was to synthesize 2-nitrophenol and 4-nitrophenol from phenol, sodium nitrate, and sodium nitrite, as well as to use column chromatography to isolate the two products from one another and the byproduct 1,4-benzoquinone. The reaction was monitored by Thin Layer Chromatography to track the progress if the refluxed reaction. Column chromatography was used as a very effective technique for separation as both solids and liquids can be separated by column chromatography. The two nitro phenol products were compared using melting point determinations and the products were also classified and checked for impurities by determination of IR and 1H NMR spectra. Results and Discussion Column chromatography is the most useful purification …show more content…
The nitro group attacks either the ortho or the para position of the phenol, due to a resonance form that puts the negative charge on either of these two carbons on the ring. This reaction competes with a side reaction that forms the 1,4-benzoquinone byproduct when the phenol is oxidized by the nitric acid. Therefore, through these reactions the three different products were formed. The reaction was monitored using Thin Layer Chromatography and the products could be clearly seen separate from the original phenol structure. The 4-nitrophenol moved the least on the TLC plates followed by the phenol, 1.4-benzoquinone, and the 2-nitrophenol move the most with the mobile phase due to hydrogen bonding within itself not allowing it to bond with silica very well. Once the phenol disappeared in the TLC product lane and became fainter in the co-spot lane it became clear that the reaction was at completion. The reaction mixture was then purified using column …show more content…
The expected melting points for 2-nitrophenol and 4-nitrophenol were 45°C and 113°C respectively and the observed melting point temperatures were 45-46.1°C and 112-114°C respectively. From the melting point it is observed that the melting points indeed match but further analysis can be taken to ensure pure product. From the IR and 1H NMR spectra we can confirm the products produced are indeed the ones intended to be made. From the IR spectra for 2-nitrophenol predicted peak values are met at 3300-3000 cm-1 (3237.56, 3113.87, and 2961.95 cm-1) for the C-H aromatic region of the product. The aromatic nitro group region around 1350 cm-1 was also observed at 1365.90 cm-1. Other expected peaks at 1583.02 cm-1 (aromatic C-C) and 1016.21 cm-1 (C-O alcohol) are also seen and there are no outlying peaks that would suggest other products as well. From the 1H NMR spectra for 2-nitrophenol, a very similar result is observed. We see multiple peaks in the 8.0-6.5 PPM region suggesting the aromatic ring and the correct 8.2 (d, 0.80 H), 7.6 (dd, 0.78 H), and 7.1 (m, 2.00 H) peaks for the ortho substituted product. We also see a very strong outlying peak at 10.6 (s, 0.87 H) representing the alcohol hydrogen in the nitrophenol along with no other strong outlying peaks except for the 2.1 PPM acetone peak. When looking at the
Lastly, the most polar molecule was the xanthophyll which received its polarity from the alcohols bonded to its conjugated chain and aromatic
In science class, we did an experiment to compare inks and their compositions. This was intended for us to learn about chromatography; the separation of a mixture through a medium (the chromatography paper) in which the components move at different rates and create different patterns. We chose to explore this topic by using four different colored markers, placing a dot of each color onto one piece of chromatography paper, and observing while the water in the beaker travels up the paper and separates the dyes. Before we started, we made a hypothesis. Mine was if paper chromatography is done on the ink in the green, red, brown, and black marker, then the green will spread out into different shades of blue and green making a pointed oval shape.
Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial.
To drive the reaction to the amide product, the reaction was performed at 300 ˚C to evaporate the water product, which is an application of Le Chatelier’s principle. Second, the aromatic nitro group was reduced to an amine using sodium dithionite. The reaction is given in Figure 1. Figure 1: Synthesis of luminol from 3-nitrophthalic acid and hydrazine. To verify the synthesis of luminol, the product was mixed with an oxidant (diluted bleach) and was inspected for a blue glow.
Abstract: The purpose of this experiment was to identify given Unknown White Compound by conducting various test and learning how to use lab techniques. Tests that are used during this experiment were a flame test, ion test, pH test, and conductivity test. The results drawn from these tests confirmed the identity of the Unknown White Compound to be sodium acetate (NaC2H3O2) because there were no presence of ions and sodium has a strong persistent orange color. The compound then will be synthesized with the compounds Na2CO3 and HC2H3O2 to find percent yield.
Aim The purpose of this lab was to separate a mixture of carboxylic acid (p- toluic acid), a phenol (p-tert-butylphenol) and a neutral compound (acetanilide) using solvent extraction. Introduction Solvent extraction is a process that separates compounds from a mixture by a solvent.
The polar silica gel in the column is the stationary phase and acts as an adsorbent, depending on the affinity of the component towards the stationary phase. In general, the more polar component would have a stronger interaction with the stationary phase, and the less polar component would be eluted out first. From the observations of the column chromatography, yellow S2 collected is β-carotene, indicating that
Then, TPP and TSPP were characterized with 13C-NMR to further examine the sulphonation process of
The possible explanations and changes to make are similar to the previous questions. Conclusion and Future Experiment 18. The identity of the product and unknown were 4-tert-butylbenzyl phenol ether and tert-butyl phenol respectively. The key to making this discovery was the melting point and TLC results!
3. Results and discussion 3.1. Exploratory experiments with MM1. In the present work, 17 ILs with different cations and anions were synthesized to evaluate the effect of different molecular structures on the extraction of N-compounds.
Through the extraction process, the mixture was separated into its pure benzocaine and benzoic acid portions. This could be proven by matching the melting points of the substituents obtained at the end of the lab to the average melting points found in several chemistry databases. In other words, the melting points of the purified benzocaine and benzoic acid compounds (93.2˚C and 131˚C, respectively) reflect a similar melting points to the documented 89˚C and 122.41˚C of the pure compounds found in nature. Although, the results was collected smoothly, the possibilities of errors are still existent. One source of error could aroused when light brown clouding forms at the interface of the two layers during acid extraction of benzocaine.
The concentration of the stock solution 2.0x 10-4M as per label information in the lab. However, the calculated volume using the experimental data is 1.5 x 10-4M.There is 25% difference between these concentration caluclated from zero time intercept. The significant difference in the concentration drop happened by many factors. First,the rate ionization is depend the pH because pKa determines the equlibrium between p-nitrophenol and its depronated form p-nitrophenolate. Although,the pH is maintained by buffer at 7,not all of the p-nitrophenol produced by the chymotrpsin catalysis is not its depronated form.
Experiment #7: Column Chromatography of Food Dye Arianne Jan D. Tuozo Mr. Carlos Edward B. Santos October 12, 2015 Abstract Column chromatography is the separation of mixture’s components through a column. Before proceeding with the column chromatography itself, a proper solvent system must be chosen among the different solvents. The green colored food dye is the mixture whose components are separated.
To demonstrate synthesis of Indigo through the Baeyer-Drewson reaction, and subsequent vat dying of cotton through conversion to and from Leucoindigo. Indigo (Vat Blue 1) is a vat dye with a molecular formula of C16H10N2O2. A characteristic of vat dyes is that they are insoluble in most aqueous environments. A reducing agent is required to convert them into a soluble “leuco” form, meaning “white” or colourless.
Column chromatography is a laboratory techniques used to isolate different compounds from one sample, in this case, it was used to isolate Aspirin and caffeine from an Anacin tablet. The Anacin tablet was dissolved in Acetone and mixed with silica get. Then column was packed with glass wool, a thin layer of sand, hexane, then a large layer of silica. An experimental issue occurred and the silica layer was not thick enough to effectively separate the mixtures. With the error the experiment continued and fractions were collected that contained caffeine and aspirin, as well as some that just contained caffeine.