Wednesday, February 27, 2019
Extraction and Evaporation Recrystallization Essay
1. To the circumstancess of a simulated pharmaceutical preparation, Panacetin, and tell aparting the un cognise broker of the multifariousness with conveyion and separation methods.2. To learn how to purify by recrystallization, how to modify them and how to obtain a melt down accuse.PRECAUTION ACETANILIDE AND PHENACETIN be EYE AND SKIN IRRITANTS. Minimize give with your transcendental obscure.THEORYIn this experiment, Panacetin, a pharmaceutical preparation entrust be separated from its components by make use of their solubilities and pungent- paper properties. Panacetin contains aspirin, sucrose and an secret component that whitethorn be either phenylacetamide or phenacetin. Of the three components, only sucrose is water- non-water-soluble in the harmoniumic solvent methylene chloride (CH2Cl2 or methylene chloride). The indissoluble sucrose can be percolateed out if Panacetin is dissolved completely in methylene chloride by juicelessness filtration or cent rifugation leaving the soluble aspirin, acetanilid and phenacetin in the issue.Although the acetanilide and aspirin are both kinda insoluble in water at mode temperature, the sodium season of aspirin is very soluble in water merely insoluble in dichloromethane. Aspirin, which is a concentrated sultry can be reborn to the salt, sodium acetylsalicylate by ex bookletion with an sedimentary root of sodium hydrogen carbonate . This salt go away migrate from the dichloromethane degree, in which it is insoluble, to the aqueous grade, in which it is soluble. The un cognize component will stay behind in the solutionand can be insulate by evaporating the solvent from the dichloromethane solution. Adding HCl to the aqueous solution restores aspirin as an insoluble white substantialness.In the tierce experiment, the identity of the unknown component of Panacetin will be purified. Purification is infallible be instance the separation procedure whitethorn be imperfect leaving trac es of depleted quantities in the complicated after separation or chemic replys may occur prior to or during the separation adding new impurities. The unknown component can be purified by recrystallization, in which an im concentrated solid dissolves in a hot (usually boil) solvent thusly crystallizes from the simmer downed solution in a purer form.METHODS/PROCEDURESThis experiment was followed from the textbook on pages 52-53 for experiment 2 and 59-60 for experiment 3 excluding the microscale part. First, weigh almost 3.00 g of Panacetin and transfer it to a clean, dry cxxv ml Erlenm midsectionr flask. Add 50 ml of dichloromethane to the flask , resurrect the mixture with a stirring rod cell to break up all lumps. When it appears that no more of the solid will dissolve, filter the mixture by gravity. stash away the undissolved solid on the filter wallpaper and particularize it aside to dry. Once it has completely dried, reweigh the solid. This compound separated by gr avityfiltration is known as sucrose.Next, transfer the dribble to a separatory funnel and ex pamphlet it with two 30 ml portions of 5% sodium hydrogen carbonate . For each ex footpathion, use a stirring rod to stir the liquid layer until any fizzing subsides before a stopper is assd on the funnel and shaken. Dichloromethane will be on the bottom layer and will be drained to a different container. Transfer the dichloromethane layer back into the funnel for the second stock. The upper layer will be transferred in an Erlenm centrer flask and will be used for recuperation of acetanilide. compounding the two aqueous solutions in the same container and acidify easy with 6M HCL to bring it to a pH of 2. Cool the mixture to room temperature or below while swirling the flask occasionally in an ice bath. Collect the aspirin by vacuum cleaner filtration. Wash the aspirin on the filter with cold distilled water. Dry the sample exhaustively before weighing and pull up stakes it in the h ood for the contiguous lab schedule.Before proceeding to recrystallization, triturate the compound with 20 ml of hexane. Crush the solid with a stirring rod and filter. Recrystallize the unknown drug component from experiment 2 by boiling it with just enough water to dissolve it completely, then letting it cool to room temperature then to 0 C. In order to induce crystallization, it would be helpful to scratch the walls of the flask so that crystals would know a progress to attach to. Use vacuum filtration to isolate the sample then dry the product to a constant mass and weigh in a tared vial.Grind a small essence of the dry unknown component to a fine powder on a watch drinking glass using a spatula. Divide the solid into four equal portions. Combine portions 1 and 2. Mix portion 3 with an nigh equal amount of finely ground acetanilide and mix portion 4 with an approximately equal amount of finely ground phenacetin. Obtain the melt down header ranges of the purified unknown (portions 1 and 2), mixture with acetanilide and mixture with phenacetin. Each melt down intend should be measured on two samples- more than that if melting compass points are imprecise or accurate.Safety Issues (all of these are taken from MSDSonline.com)1. acetanilid potential Acute pitchuate Hazardous in shell of eye contact (irritant), of ingestion, of inhalation. S blowsyly hazardous in case of flake contact(irritant).Potential Chronic Health set up Hazardous in case of eye contact (irritant), of ingestion, of inhalation. Slightly hazardous in case of skin contact (irritant).2. Phenacetin mettle and skin irritant3. DichloromethanePotential Health EffectsInhalationCauses uncomfor control boardness to respiratory tract. Has a strong narcotic effect with symptoms of mental confusion, light-headedness, fatigue, nausea, vomiting and headache. Causes formation of carbon monoxide in blood which affects cardiovascular system and central nervous system. Continued pic may mak e change magnitude light-headedness, staggering, unconsciousness, and even death. Exposure may do work the symptoms of angina (chest pains) worse. Ingestionwhitethorn typeface passion of the gastrointestinal tract with vomiting. If vomiting turn outs in aspiration, chemical pneumonia could follow. Absorption through gastrointestinal tract may bring in symptoms of central nervous system depression ranging from light headedness to unconsciousness.Skin pertainCauses irritation, redness and pain. Pro yearned contact can cause burns. Liquid degreases the skin. may be mantled through skin.Eye meetingVapors can cause eye irritation. Contact can produce pain, inflammation andtemporal eye damage.Chronic ExposureCan cause headache, mental confusion, depression, liver effects, kidney effects, bronchitis, loss of appetite, nausea, lack of parallelism, and visual disturbances. Can cause dermatitis upon prolonged skin contact. Methylene chloride may cause cancer in humans. Aggravation of Pre-existing ConditionsPersons with pre-existing skin disorders, eye problems, impaired liver, kidney, respiratory or cardiovascular function may be more hypersensitised to the effects of this substance.4. AspirinEye ContactModerate Eye anger Signs/symptoms may hold redness, swelling, pain, tearing, and blurred or hazy vision. Skin ContactModerate Skin Irritation Signs/symptoms may include localized redness, swelling, itching, and dryness. May be absorbed through skin and cause target organ effects. InhalationNo health effects are expected.IngestionMay be harmful if swallowed.Gastrointestinal Irritation Signs/symptoms may include group AB pain, nausea, diarrhea and vomiting. repeated ingestion may causeMay be absorbed following ingestion and cause target organ effects. place Organ EffectsProlonged or repeated exposure may causeAuditory Effects Signs/symptoms may include hearing impairment, balance dysfunction and ringing in the ears. Clotting Disorders Signs/symptoms may inc lude increase blood clotting time and internal bleeding (hemorrhage). Liver Effects Signs/symptoms may include loss of appetite, weight loss, fatigue, weakness, abdominal tenderness and jaundice. rudimentary Nervous System (CNS) Depression Signs/symptoms may include headache, dizziness, drowsiness, incoordination, nausea, slowed reaction time, thickheadedspeech, giddiness, and unconsciousness. Kidney Effects Signs/symptoms may include reduced or absent peeing production, increased serum creatinine, humble back pain, increased protein in urine, and increased blood urea nitrogen (BUN). Pulmonary Edema Signs/symptoms may include chest discomfort, shortness of breath, significant cough with frothy sputum production, racy colored skin (cyanosis), increased heart rate, respiratory failure and may be fatal. Single exposure may causeImmunological Effects Signs/symptoms may include alterations in the number of circulating immune cells, supersensitised skin and /or respiratory reaction, and changes in immune function.5. Sodium bicarbonateEMERGENCY OVERVIEWWarning May cause respiratory tract irritation. Causes eye and skin irritation. sucker Organs Blood, kidneys, heart, liver, eyes, skin.Potential Health EffectsEye Causes eye irritation.Skin Causes skin irritation. May be harmful if absorbed through the skin. Ingestion May be harmful if swallowed. Causes gastrointestinal tract irritation. Inhalation May cause respiratory tract irritation. May be harmful if inhaled. Chronic May cause liver and kidney damage. Adverse fruitful effects have been reported in animals. Laboratory experiments have resulted in mutagenic effects. Chronic exposure may cause blood effects.6. Hydrochloric iratePOTENTIAL HEALTH EFFECTSInhalation May cause irritation (possibly severe), chemical burns, and pulmonary edema.Skin contact May cause irritation (possibly severe) and chemical burns.Eye contact May cause irritation (possibly severe), chemical burns, eye damage, and blindness.Ingestion Not a likely route of exposure.Target Organs Effected Respiratory System, Skin, EyeChronic Effects Repeated or prolonged exposure to dilute solutions may result in dermatitis. Discoloration of the teeth may occur as a result of long term exposure.Interaction with Other Chemicals Which Enhance Toxicity no(prenominal) known Medical Conditions Aggravated by Exposure None knownOBSERVATIONS/RESULTSIn Experiment 2, the extraction of substances from one another is based on the differences in their physical and chemical properties. Approximately, 3.0029 g of panacetin was weighed and completely dissolved in 50 ml of dichloromethane and filtered. The residue was left to dry and weighed (sucrose). thus 30 ml of NaHCO3 was added to the filtrate. This solution was transferred into a separatory funnel. This formed two layers. crystallise layer was the organic layer (NaHCO3) described as a assoil liquid. Bottom layer was the aqueous layer and was yellow in color. The filtrate was washed twic e with NaHCO3. HCl was added to the aqueous solution until the pH equaled to 2.0. It was filtered through vacuum filtration and allowed to dry until the next weeks lab. This filtrate is known as aspirin. Meanwhile, the unknown in the organic layer was also allowed to settle for the next experiment.In experiment 3, before we went to do recrystallization, we first did trituration of the unknown by adding 20 ml of hexane. We crushed the solid and filtered. Even with the accompaniment of approximately 27 ml of boiling water into the compound, it started to dissolve. That was the first clue that we have acetanilide as our unknown. We went ahead and continue heating and swirling the solution all over a hot plate. There was the formation of brown oil-like globules. We were then asked to pullulate the clear liquid from this solution. This clear liquid was allowed to cool to room temperature then to 0 C. There was formation of white crystals at the edge of the beaker. by dint of vacuum f iltration, we were able to filter the product, weighed and used for melting point criterion of the unknown.The solid was divided into 4 equal split. First 2 parts were combined, 3rd part was manifold with acetanilide and the last part was mixed with phenacetin. by and by taking the melting points of all these 3 substances we were able to identify the unknown product to be acetanilide.No big issues encountered during this experiment. Transferring some products as well as the final crystals from watch glass and filter paper and leaving some products were crucial to get the most final product. This rationalizes why the percent recovery for the unknown was low. Some crystals fell off or didnt transfer to the filter paper. Even though the % recovery was comparatively low (88.4079%), this experiment still produced a 0.6898 g of product.DISCUSSION/ resultThis experiment was focused on two main objectives. First, the analysis of panacetin to expose out what percentages of sucrose, asp irin and the unknown component it contains. Second, to find out whether the unknown is acetanilide and phenacetin. A big part of the composition of panacetin was made up of the unknown. We were able to determine the composition of sucrose to be 17.95 %, Aspirin 26.93% and the unknown to be 55.12% After following the experiment procedures, we were able to purify through recrystallization the end product to be acetanilide. This is an odorless white crystalline solid substance which has a melting point of 114 C. Our experimental value for acetanilides melting point was 117 which indicates that the result had a very specialise range and close to the literature value. I would therefore conclude that we had isolated a close to pure product of acetanilide with little impurities present.1. a. let on any evidence that a chemical reaction occurred when you added 6 M HCl to the solution of sodium acetylsalicylateA chemical reaction took place upon the addition of 6M HCl to a solution of sodi um acetylsalicylate because a precipitate formed known as aspirin.b. Explain why the changes that you observed took place.The observed change took place as a result of the acid reacting with the salt forming a compound insoluble in water.2. Describe any explain the possible effect on your results of the following experimental errors or variations. In each case, mold the component (s) whose percentage(s) would be too high or too low.a. After adding dichloromethane to Panacetin, you didnt stir or shake the mixture long enoughImproper stirring or shaking of the mixture will result in incomplete dissolution of the panacetin mixture. There will be loss of some solid analytes during filtration. The recovered amounts will be lower than they should be leading to a final percentage to be low.b. During the NaHCO3 extraction you failed to mix the aqueous and organic layers thoroughly.If the aqueous and organic layers were not thoroughly mixed the acid would remain in the solution and the extr action would be less efficient resulting to a low percentage yield.c. You mistakenly extracted the dichloromethane solution with 5 % HCl ratherthan 5 % NaHCO3.If 5% HCl is used sort of of 5% NaHCO3 that would protonate the aspirin and keep it in the organic solution making the aspirin, acetylsalicyclic acid.d. Instead of using pH paper, you neutralized the sodium bicarbonate solution to pH 7 using litmus paperAt ph7 the bicarbonate wouldnt be able to act as a base and extract a proton because at pH of 7 it would protonate itself so it wouldnt be able to react with aspirin.5. Write a balanced reaction equations for the reactions involved a. When aspirin dissolves in aqueous NaHCO3C9H8O4 (aq) + NaHCO3 (aq) C9H7O4Na (aq) + CO2 + H2O timid acid weak base Strong ancestor Strong acidb. When Aspirin is precipitated from a sodium acetylsalicylate solution by HCLC9H7O4Na + HCl - C9H8O4 + NaCl Strong Base Strong acid Weak Acid Weak Base take for granted that both reactions are spontaneous under the standard conditions, label the stronger acid, stronger base, weaker acid and weaker base in each equation.Experiment 31. a. What is the minimum people of boiling water needed to dissolve 0.200 g of phenacetin?b. astir(predicate) how much phenacetin will remain dissolved when the water is cooledto room temperature?c. Calculate the maximum mass of solid (undissolved) phenacetin that can be recovered when the cooled solution is filtered.0.200 g-0.0125 g (amount soluble in cold water)= 0.1875 g2. An unknown compound X is one of the four compounds listed in table 3.2. A mixture of X with benzoic acid melts at 89 C, a mixture of X with phenyl succinate melts at 120 C and a mixture of X with m-aminophenol melts at 102 C. Give the identity of X and explain your reasoning.X is phenyl succinate.When a compound mixes with a different compound, the melting point of the mixture will be lower than the melting points of either of the pure compounds. Basing from the table, the melting point of pure benzoic acid is 121 C but when mixed to X, it went down to 89 C. Likewise with O-toluic acid and m-aminophenol. Since the melting point of mixture X with phenyl succinate has a melting point of 120 C, the melting point of pure X must be equal or closer to 121. Mixing X with phenyl succinate did not change the melting point thus X must be phenyl succinate.