Dates of the experiment: Add the date of the experiment
The objective of the experiment
Analgesic medicines are made up of aspirin, acetanilide, and sucrose. The above components were isolated using acid-base extraction. As such, these compounds were separated based on how they dissolved in liquids and reacted with other chemicals. The lab test was aimed at separating the different components of Phensuprin drug, which is an analgesic drug. The drug was made up of aspirin, acetanilide, and sucrose. Aspirin and acetanilide were used as analgesic elements. Sucrose was utilized as fillers. After the lab experiment, the percentages of these constituents were evaluated. Its melting point indicated the purity of each compound. Indicated below are the primary objectives of undertaking the analysis:
- The experiment was aimed at identifying the components of Phensuprin
- The demonstration was aimed at comprehending acid-base extraction process
Physical properties, structures, and hazards of all reactants and products
Sucrose is a solid white carbohydrate. It had a molar mass of 342.3 g/mol and a melting point of 366.8°F/186°C1. With respect to its hazard, it was noted that the compound was an irritant. Indicated below is a chemical structure of sucrose:
The product is a white gray solid. It has a molar mass of 135.197 g/mol and 113-115 °C. Concerning its health hazards, it was noted that the compound was toxic and caused irritation2. Indicated below is a chemical structure of acetanilide:
- Acetylsalicylic acid
The compound is also called aspirin3. It is a white crystal-like solid. It exhibited a melting point of 134-136°C and a boiling point of 140°C. It had a molar mass of 180.157 g/mol. The product was irritant and poisonous. Indicated below is the chemical structure of aspirin of acetylsalicylic acid:
The compound is also known as methylene chloride. The compound existed in liquid form. It had a molar mass of 84.93 g/mol and a boiling point of 39.8-40°C. It is extensively utilized as a solvent. The compound was the least poisonous of the simple chloro-hydrocarbons4. The component was toxic, flammable, and an irritant. Indicated below is the chemical structure of dichloromethane:
- Sodium bicarbonate
The product is an inorganic solid characterized using the formula NaHCO35. It is crystal-like solid. It had a melting point of 270°C. Its molar mass was 84.01 g/mol. It was a toxic and an irritant substance. The chemical structure of sodium bicarbonate is illustrated below:
- Sodium sulfate
The solid substance had a molar mass of 142.04 g/mol. It had a melting point of 623°F (884°C)6. The compound was an irritant. The chemical structure of sodium sulfate is illustrated below:
- Hydrochloric acid
HCL is a strong, pale, and very sharp-tasting liquid7. The solution comprised of a combination of HCL and water. It had a molar mass of 36.46 g/mol. Its boiling point was 108.6 °C (227 °F). Similarly, it had a density of 1.2 g/mL at 25 °C. It was an irritant and a poisonous substance. It had the risk to impair respiratory organs, eyes, skin, and bowels permanently. Indicated below is the chemical structure of hydrochloric acid:
Phensuprin weighing 2.00 grams was added into a 125 ml Erlenmeyer flask with the capacity of 125 milliliters. Later, 50.0 ml of dichloromethane of 50ml was poured into the flask and briskly stirred. The solution was shaken until no solid appeared to dissolve. Afterward, a piece of paper was weighed and fluted. The concoction was filtered through the pre-weighed filter paper. The filtered solid was then mixed with 5.0 ml of dichloromethane. Later, the filter paper enclosing the collected sucrose was placed in a beaker to dry for seven days.
When the filter paper and the sugars were completely dry, they were weighed. After that, the amounts of sugars recovered were calculated. The results were reported as mass and percentages with respect to the total weight of Phensuprin. To separate aspirin a filtrate was added. The filtrate comprised of the dichloromethane solution. The mixture was extracted using a separatory funnel and sodium bicarbonate solutions. To achieve this, a portion of sodium bicarbonate solution was added to the funnel comprising of the dichloromethane solution.
Afterward, the funnel was stoppered. A finger was placed over the stopper to keep it in position while shaking the funnel gradually for about 3 minutes. Every few seconds, the funnel was overturned as its stopcock was opened to discharge the pressure. While doing so, care was taken to enhance safety. As such, the tip of the funnel was faced away from the students before pressure was freed. Afterward, the stopcock was closed and the funnel shaken continuously.
After the extraction period had expired, the pressure was released before the stopcock was shut, and the funnel positioned in a clamp. After that, the stopper was isolated. Immediately the deposits get detached, the lower layer comprising of dichloromethane were drained into a 125.0 ml Erlenmeyer flask. Subsequent to the removal of the dichloromethane layer, the stopcock was shut. Then, the aqueous layer was poured out of the funnel into a 400.0 ml beaker. Afterward, the dichloromethane layer was returned into the funnel, and the process reiterated using the second ration of sodium bicarbonate solution. Later, the two aqueous deposits were combined before the dichloromethane cover was saved for the last stage.
The two aqueous coatings were then cooled in an ice immersion. With the help of transfer pipet, 10.0 ml of concentrated HCL were gently added while stirring. At this stage, foaming was expected. The solution was further cooled in ice immersion up to the time the solid acetylsalicylic acids were formed. The solid particles were collected using vacuum filtration process. After that, the filtrate was collected using 5.0 ml of cold water. To totally dry the solid, the vacuum was kept running for numerous minutes after the filtration process was finished. Later, the collected solid was moved to an un-capped taster vessel to dry for a week. After the solid had dried, the mass of acetylsalicylic acid recuperated was recorded in terms of the Phensuprin components.
During its conclusion stages, the residual organic mixture was dried over anhydrous sodium sulfate. A portion of the anhydrous sodium sulfate was decanted into a solution of methylene chloride and whirled. Throughout the process, the hydrating agents fastened together. Sodium sulfates were introduced in small percentages until a portion of dehydrating agents flowed freely. Afterward, the mixture was whirled for some minutes before being sifted into a sterilized and dry round bottom 100.ml container. After that, the methylene chloride was vaporized using a rotating evaporator. The process continued until all the solvent had been eliminated. Acetanilide constituent was left behind as solid specks. The residues were saved in the un-stoppered plump-bottomed container for the following lab period. In the following lab, all the solids had dried. The solids were then evaluated.
Calculation theoretical and percent yield of all the three compounds
After the extraction process had been completed, each component recovered was evaluated. The results were reported based on the mass and percentage of the entire weight of the Phensuprin. The melting point of every constituent was recorded and compared with the standard figures to assess the purity of every component of Phensuprin. The compositions were calculated using the formula (Percent recovery = (actual recovery (g)/ theoretical recovery (g)) x 100). My calculations are indicated below:
Mass of the Phensuprin: 2.0g
Mass of the filter paper used to separate the sucrose: 0.96g
Mass of the filter paper+ sucrose: 1.012g
Mass of sucrose obtained: 0.052g
Mass of acetanilide obtained: 0.797g
Mass of the round bottom flask: 59.9g
Mass of acetylsalicylic obtained: 0.53g
Total mass: 0.052+0.797+0.53= 1.379g
Total percent recover: (1.379g/2.0 ) x 100= 68.95%
Percent composition of sucrose: (0.052/1.379) x100= 3.77%
Percent composition of acetanilide: (0.797/1.379) x100= 57.7%
Percent composition of acetylsalicyclic: (0.53/1.379) x100= 38.43%
A short synopsis of the results obtained
Notably, the melting of sucrose was already known. The mass of sucrose was found to be 3.77% composition of the total mass. The melting point measured for aspirin was 104 °C. The above figure does not match the ideal melting point indicated in literatures, which is 134-136 °C. The results differed because the compound had impurities. Aspirin percentage obtained was 38.43%. Acetanilide had a melting point of 114 °C. The figure correspondent with the ideal melting point indicated in literatures, which ranges from 113-115 °C. The above indicate that the compound was free from impurities. The component had a percent composition of 57.7% of the total mass. The total percent recovery was 68.95%. The above imply that substantial amounts of the three constituents were recovered from Phensuprin sample. As such, gravity filtration was noted to be beneficial when eliminating negligible amounts of solid contaminations from a solution unlike vacuum filtration.
The first stage of the experiment comprised of separation. During this stage, it was noted that sucrose dissolved easily in water. Acetylsalicylic acid and acetanilide did no dissolve in water. However, the two components were soluble in dichloromethane. Sucrose was insoluble in dichloromethane. To begin, Phensuprin was mixed with dichloromethane. Next, sucrose was separated through a filtration process. Subsequently, dichloromethane was isolated using sodium bicarbonate. The salt was dissolved in water enabling the separation of acetanilide. As such, acetanilide was not interfered with the sodium bicarbonate solution. Therefore, the constituent remained dissolved in the dichloromethane. Because water and dichloromethane do not mix, the deposits were isolated with ease to get two different analgesic components. The acetylsalicylic acid was finally recovered by transforming the salt back to its initial form using concentrated HCL solution.
When the separation of the three components had been undertaken, their melting points were analyzed to evaluate if they contained contaminations. The experiment above isolated the different constituents of the drug. The products separated were aspirin, acetanilide, and sucrose. Aspirin acts analgesic element. The above components were isolated based on the dissimilar solubility and reactivity of each respective constituent. After that, the quantity of each component in the mixture was determined.
Throughout the stirring process, attention was taken to ensure that no clumps of solid were broken. The beaker was swirled amid the hydrochloric acid additions. After the addition process had been done, the PH levels of the solution were evaluated and recorded. The process was conducted by introducing a glass bar into the solution. The solution at the end of the glass was placed on a portion of the PH paper. When the PH level was above 2, small amounts of HCL were added into the solution up until the levels dropped below 2. The PH level of two indicated concentrated hydrochloric acid. Sodium sulfate was used as a drying agent. Indicated below are some of the reactions that was realized during the experiment. The acetylsalicylic solution was reacted with sodium bicarbonate to form salt as indicated below:
When HCL was mixed with oxidizing agents like sodium hypochlorite or potassium permanganate, chlorine gas was emitted as indicated below.
NaClO + 2 HCl → H2O + NaCl + Cl2
2 KMnO4 + 16 HCl → 2 MnCl2 + 8 H2O + 2 KCl + 5 Cl2
PbO2 + 4 HCl → 2 H2O + PbCl2 + Cl2
When NaHCO3 was reacted with HCL a salt and a carbonic acid was released as indicated below:
NaHCO3 + HCl → NaCl + H2CO3
H2CO3 → H2O + CO2 (g)
The errors experienced in the lab experiment were human and calibration errors. Human errors were brought about by recording incorrect measurements, accidentally contaminating reactants with other substances, and using adulterated instruments.
Answer the following questions
- The original organic solution was extracted two times with aqueous sodium bicarbonate. After the extraction, what compound(s) were in the organic layer? What compound(s) were in the aqueous layer?
After the introduction of NaHCO3, acetanilide stayed in the organic deposit. Acetylsalicylic acids were found in the aqueous layer.
- Assume that both acetylsalicylic acid and acetanilide are soluble in diethyl ether, and that diethyl ether was used in place of the methylene chloride. Would the ether layer be the bottom layer in the separatory funnel or the top layer? Explain your answer.
Ether layer It will be the top layer of the separatory funnel because diethyl ether is less dense than water.
- Assume that both acetylsalicylic acid and acetanilide are soluble in methanol, and that methanol was used in place of the methylene chloride. What problem(s) might occur during the extractions? (Careful, this is a trick question.)
Methanol is immiscible in water. Through this, it will be difficult to separate acetylsalicylic acid and acetanilide from the solution hence complicating the separation process.
- The solid deposit that is left after the methylene chloride solution is vaporized has a lower melting point that its ideal value indicated in books, due to contaminations. Explain what impurities are present and why?
The remains will comprise of acetylsalicylic acid since the extraction is not a suitable method of purifying mixtures of organic components.
Lilley, Linda. Study Guide For Pharmacology And The Nursing Process. London: Elsevier Health Sciences, 2013. Print.
Pavia, Donald. Introduction to Organic Laboratory Techniques: A Microscale Approach. Belmont, CA: Thomson Brooks/Cole, 2007. Print.
- Linda Lilley. Study Guide For Pharmacology And The Nursing Process. (London: Elsevier Health Sciences, 2013. Print) 67.
- Donald Pavia. Introduction to Organic Laboratory Techniques: A Microscale Approach. (Belmont, CA: Thomson Brooks/Cole, 2007. Print) 56.
- Donald Pavia. Introduction to Organic Laboratory Techniques: A Microscale Approach. (Belmont, CA: Thomson Brooks/Cole, 2007. Print) 123.
- Linda Lilley. Study Guide For Pharmacology And The Nursing Process. (London: Elsevier Health Sciences, 2013. Print) 45.
- Donald Pavia. Introduction to Organic Laboratory Techniques: A Microscale Approach. (Belmont, CA: Thomson Brooks/Cole, 2007. Print) 67.
- Linda Lilley. Study Guide For Pharmacology And The Nursing Process. (London: Elsevier Health Sciences, 2013. Print) 89.
- Donald Pavia. Introduction to Organic Laboratory Techniques: A Microscale Approach. (Belmont, CA: Thomson Brooks/Cole, 2007. Print) 32.