The Thin layer chromatography is one of the oldest techniques which is used to identify what is present in an unknown mixture. It is a very useful technique for research,forensics,environmental testing, and many more fields because it is simple and inexpensive way to analyze small samples. In this experiment two compounds (solid) were used ferrocene and acetylferrocene. In the first step 50 ml of 2:8 diethyl ether/petroleum ether was placed in an erlenmeyer flask covered with a parafilm paper to avoid evaporation. Then the glass column was prepared placing a small cotton on the bottom of the glass column and then added a small amount of sand , wich will give the stationary phase an even base and prevent concentration and streaking of the bands …show more content…
Later we weighed 0.150g of 1:1 ferrocene and acetylferrocene(orange) mixture and we added silica, we mixed it together. This mixture was placed into the column adding solvent not letting it get dry. Immediately we noticed the yellow color traveling down the slurry. When it was close enough to the bottom of the column, it was drained into beaker #1. Then the white part was transfer to beaker #2, which was our trash beaker, this step is necessary to make that part of the orange does not contaminates the yellow part to prevent impurities. At this point 2:8 solvent was over, therefore we used 1:1 solvent which has a higher polarity. Then we drained the orange part to beker …show more content…
To prepared the silica gel plate we used the sample drained from beaker 1, beaker 2, and a mixture of ferrocene and acetylferrocene provided to us in the lab. The solvent traveled 5.6 cm and the mixture given of acetyl ferrocene and ferrocene gave us two dots, one yellow which travelled 4.3 cm, with an Rf value of 0.767. The other spot (orange) travelled 2.3 cm with an Rf value of 0.410 cm. Then beaker # 1 (yellow spot) which was ferrocene travelled 4.5 cm, and the Rf is 0.803 . Beaker #3 (orange spot) which was acetylferrocene travelled 2.5 cm and the Rf value is 0.446.The two beakers with the rest of the sample was left on the storage and one week later we weighed the amount recovered. For ferrocene we recovered 0.069g which represented 46% of the initial amount we used (0.150g),we confirmed that the compound we were using was pure obtaining a sharp mp of 175.8-177.1 on the first try and then
Therefore, it is expected that the methyl meta-nitrobenzoate would be the product formed faster and in greater quantities because it has the more stable intermediate. Thin layer chromatography uses a solvent (in this case 85% hexane–15% ethyl acetate) to separate different products based on differences in polarity of the molecules. Typically more polar compounds will have more interaction with the stationary phase, and will not move as from the solvent front. This means that the less polar a substance is, the farther it will move. Using the mechanism of electrophilic benzylic substitution, it can be determined at where each step of the mechanism is occurring, and at what procedure it is occurring at.
Once the mixture had been completely dissolved, the solution was transferred to a separatory funnel. The solution was then extracted twice using 5.0 mL of 1 M
The IR spectrum RM-02-CC2 was obtained. The spectrum consisted of a carbonyl peak, an aromatic carbon-carbon double bond peak, and a sp2 hybridized carbon and hydrogen bond peak at 1713, 1598, and 734. These functional groups are all present in 9-flourenone. The carbonyl group specifically was important because fluorenone was the only that contained a carbonyl group. The Identity was further confirmed by the melting point, 79-80˚C. This value is similar to the known value 84˚C2. The melting point observed during the experiment is greater than the known because the sample is slightly impure. This impurity is caused by presence of fluorene on the tip of the columns. As stated before, the tip of the column needs to be manage to ensure pure products. The presence of fluorene would increase the temperature as seen in the melting point results because the melting point of this compound is greater than fluorenone. Overall, both compounds were separated with column chromatography and presented reasonable yields for both products. Column chromatography is a useful technique to separate mixtures with both large and small quantities. Unlike TLC, column chromatography and be used for large amounts of
Use blue LED color for maximum absorbance of Ferroin and scroll down the colorimeter screen to view absorbance at your chosen wavelength. Measure the initial absorbance of the mixture with colorimeter, record it and use this information to determine the molar extinction coefficient for Ferroin. Place the cuvette into 40°C water bath and let it heat up. Remove cuvette from water bath to measure the absorbance of mixture with two minutes of interval in between, putting the cuvette immediately back after the measurement. Be sure to dry the cuvette (ex. with paper towel) before putting into colorimeter. Continue until the absorbance drops below 0.2 or when you have the 10th measurement. For second experiment, repeat procedure using 0.20M sulfuric acid by diluting 0.40M sulfuric acid. For the last experiment, use 0.40M sulfuric acid again but put into 45°C water bath instead of
In the second experiment with the green color, I can safely conclude that the color green in this case is very soluble and we would need longer filter paper, perhaps more time to safely separate the different colors that make up the color green.
There are a number of examples of works done before the twentieth century in which experiments were conducted. However, Michael Tswett used column liquid chromatography in which the stationary phase was a solid adsorbent packed in a glass column and the mobile phase was a liquid. He conducted experiments on extracts of chlorophyll in gasoline oil over 100 adsorbents. Most of these adsorbents are now no more important. Interestingly, the list of the inclusion of materials such as silica, alumina, carbon, calcium carbonate, magnesia and sucrose are still in use. He also confirmed the identity of the fractions obtained by the spectrophotometry at different wavelengths thus anticipating the most common mode for in liquid chromatography. In 1910 Tswett obtained his Doctrate degree and his doctoral research paper was published as a monogram which once again demonstrated his ideas for further development and improvement. That monogram marked the end of his chromatographic work. This is not surprising, because he was a botanist and chromatography is only a means and not an end. Chromatographic techniques had been ignored until 1930. One of the few exceptions was the work of an American L.S. Palmer, who in 1930 published his work for the description of the separation af plant and other dairy pigments. There are several reasons for the lack of interest in chromatography , for the moment, the main thing is that it
An alcoholic beverage such as whiskey is a source of ethanol, but with different brands there will be a complex blend of trace impurities. Gas Chromatography is an inexpensive apparatus separation is based on partition between mobile phase and stationary phase. Major components used in gas chromatography are gas inlets, injector, column, detector and amplifier. Detector used in FID, flame ionization detector that uses a flame in the column for the compounds exiting gas chromatography.2 The combination of two methods is called GC/ FID, used for the separation of many organic compounds,
== Refer to, Chemistry Lab #1 – What’s the substance? However, I changed some of procedures during my experiment, here is the changes I made in this experiment: * I only used the toothpick to place a small amount of each sample on a separate piece of paper, instead of the spatula.
Begin collecting samples with the pure hexane. Keep adding hexane so that the silica gel column does not run dry. Collect one 20 ml sample. Repeat with 90:10 hexane and collect 4 20-mL bottles. Repeat with 80:20 hexane and collect 2 20-mL samples.
Thin layer chromatography is done by placing samples on a chromatography plate, which is then placed in a beaker into a solvent. The solvent then crawls up the plate through capillary action and takes the samples with it through intermolecular forces. The sample should then drop out of the solvent at some point, depending on the strength of the attraction to the solvent versus the strength of the attraction to the chromatography plate. More polar substances should be attracted to the chromatography plate, which is coated in silica gel, whereas less polar substances should be more attracted to the solvent. Rf values, which are the distance the solute travels from the baseline divided by the length of the solvent front, are then calculated, with the more polar substances being closer to 1. These Rf values ensure that the data is accurate and consistent, even when the solvent fronts are different
By providing the different times molecules move through the charged column, gas chromatography can be used to identify and determine the amount of ethanol in gasoline. The signals
To the first Erlenmeyer flask with the ferrous salt add about 1/3 of the 0.75N sulfuric acid. Dissolve the salt by gently swirling it in the dilute acid. Add about 5mL of the Zimmerman-Reinhardt Reagent (this reagent contains phosphoric acid which complexes yellow ferrous ions into colorless compounds which do not obscure the endpoint; it also contains manganous ions which inhibit the oxidation of any chloride ions in the sample). The use of a white background underneath the flask aids in the detecting of the endpoint. Repeat with second sample.
Continue this process until a vibrant pink color remains. Record the final volume of the solution and calculate molarity. Repeat this procedure two more times and receive an average of all trials. Part 2: Identification of an Unknown
Stationary phase is of extreme importance in an HPLC analysis, as the chemical nature of the same and its compatibility with the analyte of interest is extremely significant for efficient separation. The most commonly used stationary phase is silica packed column which acts as a adsorbent. Each component in the sample interacts with these silica particles and gets eluted out in different time intervals. These silica columns may be of C14 or C18 type depending on the component of interest and also the columns themselves come in various dimensions each with a specific purpose of analysis.
Should Legal Immigration be maintained? Have you ever thought about the increasing number of population in your country? In the past few years, the population of any country has been on the rise. This is a major problem that faces many countries all over the world and may have serious complications, the main reason for this is the increasing number of immigrants. The reason behind their immigration varies from one person to another.