Formal Report
Laboratory Skills in Inorganic and Organic Chemistry
Aim
The aim of this experiment is to synthesise aspirin through esterification and how to purify it using the recrystallization method. It is also to distinguish aspirin by determining the melting point.
Hypothesis of the characterized aspirin:
The aspirin should be white and shiny in appearance and it should have a melting point of estimated 139degrees celcius.
Introduction
Aspirin is one of the most common drugs that does not require prescription. It is a salicylate. It effectively diminishes the pain of problems such as headaches, toothaches and joint pains. It works by reducing substances in the body that cause fever, pain and inflammation. salicylic acid (C7H6O3) + acetic
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Some product will be dissolved while washing. Cold water is used instead of warm water to reduce the amount of dissolving the product.
• The synthesis uses different temperatures because when using warm water, which is at a higher temperature, molecules move more quickly and collide which each other more as they have more kinetic energy which increases the solubility of the aspirin. Using an ice bath slows down the molecules, enabling them crystallize.
The aspirin is characterized by melting point at the end. To check whether the product is pure, the melting point range should be minimal.
Procedure
Synthesis of the aspirin:
1. 2g of salicylic acid is weighed in a dry 100ml conical flask using a top-pan balance. The actual weight is recorded.
2. In the fumehood,5mL of acetic anhydride is added to salicylic acid in the flask. An ester and water will be formed.
3. To this mixture,3-4drops of concentrated sulfuric acid is added and the mixture is swirled. This will speed up the reaction. salicylic acid + acetic anhydride
(ethanoic anhydride) [H2SO4]
→ aspirin
(acetylsalicylic acid) + acetic acid
(ethanoic
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The crude product is dissolved completely in 5mL of ethanol to form a hot saturated solution. If necessary, the solution is warmed. Do not let it boil. Recrystallization is performed to purify the aspirin which is usually done by dissolving the substance in a suitable solvent, which is hot.
8. Approximately 30mL of hot distilled water is added into the solution on a hotplate one the solid dissolves. 1mL of ethanol is added and warmed gently if the solid reappears, until the solid dissolves completely. (the solution should be completely clear)
9. The solution is cooled to room temperature and then it is placed in an ice-bath in the fumehood for approximately 10-15mins. The solution is not to be agitated while cooling. Using an ice bath slows down the molecules in the solution, enabling them crystallize.
10. A clean, dry watch glass with two pieces of filter papers are weighed and recorded.
11. The recrystallized products are obtained by suction filtration using our weighed filter paper.
12. The crystals and filter paper are transferred onto the watch glass. At 100degrees Celsius, the crystals are dried for 15-20mins.
13. For 5-10 minutes, the crystals, filter paper and watch glass are placed in a
(Why Does Alka-Seltzer Fizz in Water?) The fizzing that occurs is basically the same as baking powder and vinegar. (Why Does Alka-Seltzer Dissolve in Water?) The chemical reaction happens when molecules collide into sufficient energy to break old bonds and form new ones. (Walker and Wood)Some of these may take a while and others may take almost no time at all. (Walker and Wood) Alka-Seltzer contains citric acid and sodium bicarbonate which is basically baking powder. (Walker and Wood) I believe that the tablets will dissolve faster in warmer water, because increasing temperature also increases kinetic energy of the reactant molecules. When the rate of the reactant molecules increases the tablets will dissolve quicker. (Walker and Wood) When Alka-Seltzer dissolves it is caused by acid coming in contact with baking soda. (Why does Alka-Seltzer
Firstly, an amount of 40.90 g of NaCl was weighed using electronic balance (Adventurer™, Ohaus) and later was placed in a 500 ml beaker. Then, 6.05 g of Tris base, followed by 10.00 g of CTAB and 3.70 g of EDTA were added into the beaker. After that, 400 ml of sterilized distilled water, sdH2O was poured into the beaker to dissolve the substances. Then, the solution was stirred using the magnetic stirrer until the solution become crystal clear for about 3 hours on a hotplate stirrer (Lab Tech® LMS-1003). After the solution become clear, it was cool down to room temperature. Later, the solution was poured into 500 ml sterilized bottle. The bottle then was fully wrapped with aluminium foil to avoid from light. Next, 1 mL of 2-mercaptoethanol-β-mercapto was added into fully covered bottle. Lastly, the volume of the solution in the bottle was added with sdH2O until it reaches 500 ml. The bottle was labelled accordingly and was stored on chemical working bench.
Looking at my results, I can see that I only obtained 86.6% of aspirin. this is not the highest percentage that it could be. I probably lost some aspirin when I had to re-filtered the solution multiple times, or when I had to weigh a new beaker and maybe not all of it got transferred over to the new beaker, or maybe I didn’t get all of the aspirin crystals off of the paper towel and into the beaker. Regardless, of where the aspirin sample was lost, I obtained a 86.6% of aspirin from this
· Rinse out mixture in flask and leave water running to get rid of the
The aspirin crystals were packed into 3 small capillary tubes to ensure that they are compressed so as to prevent any air gaps. Subsequently, the aspirin crystals that are in the 3 capillary tubes are placed into the melting apparatus and the temperature range was recorded. Since the range is quite far from the theoretical value of 140°C, aspirin's purity attained was low due to impurities present. One potential reason is because of the swift cooling. When the aspirin is left to cool, the crystal lattices will form too rapidly which will surround other molecules thus making the aspirin impure. Another reason could be because the recrystallized aspirin has not dry completely and there might me left over solvent that will affect the temperature range of the aspirin.
Aspirin contains the substance acetylsalicylic acid (ASA), which can relieve inflammation, fever, pain, and known as a “blood thinner”. Aspirin was not officially trademarked until March 6, 1899 when the Imperial Office of Berlin made it official. It has been used for the last 110 years, but its natural form, salicylic acid has been around for thousands by Egyptians, Greeks, and Romans. Aspirin is available in over 80 countries and known as the best non-prescription drug. The most common use of aspirin is to cure headaches and use it as a pain reliever, but aspirin is known to prevent heart attack and strokes. It was first proposed in 1940, but wasn’t confirmed until 1970 when doctors would recommend taking aspirin daily [1].
7. Using the stirring wire, stir the mixture until the solute completely dissolves. Turn the heat source off, and allow the solution to cool.
The purpose of this experiment was to learn and preform an acid-base extraction technique to separate organic compounds successfully and obtaining amounts of each component in the mixture. In this experiment, the separation will be done by separatory funnel preforming on two liquids that are immiscible from two layers when added together. The individual components of Phensuprin (Acetylsalicylic acid, Acetanilide, and Sucrose as a filler) was separated based upon their solubility and reactivity, and the amount of each component in the mixture was obtained. Also, the purity of each component will be determined by the melting point of the component.
Paragraph 2: It is believed that as the temperature of the water increases the time it will take for the tablet to dissolve will decrease. This is believed since the temperature there will be more energy allowing the particles to get together and form a reaction allowing the ta...
The conical vial was placed in a small beaker and allowed to cool to room temperature. The mixture was Cooled thoroughly in an ice bath for 15-20 minutes and crystals collected by vacuum filtration on a Hirsch funnel. The vial was rinsed with about 5 mL of ice water and transferred into to the Hirsch funnel and again washed with two additional 5mL portions of ice water. Crystals were dried for 5-10 minutes by allowing air to be drawn through them while they remained on the Hirsch funnel. The product was transferred to a watch glass plate and allow the crystals to dry in air. Crude acetaminophen product was weighed and set aside a small sample for a melting point determination and a color comparison after the next step. Calculation of the percentage yield of crude acetaminophen (MW = 151.2). was done and recorded in the lab notebook.
In a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved.
Mixed melting point was used to confirm the identity of the product. The smaller the range, the more pure the substance. When the two substances are mixed; the melting point should be the same melting range as the as the melting range obtained after filtering. If the mixed melting point is lower one taken from the crystals, then the two substances are different.
Background Information Aspirin is an analgesic (pain relieving) and an antipyretic drug (a drug that lowers body temperature). The main constituent of aspirin is 2 - ethanoythydroxybenzoic acid, also known as acetylsalicyclic acid (shown below right). It was originally made from just salicylic acid (which is found in the bark of a willow tree) when used by the Ancient Greeks to counter fever and pain, but its bitterness and tendency to irritate the stomach caused problems. These were resolved by the German chemist Felix Hoffman, who made the acetyl derivative of salicylic acid in the
2nd step heat the mixture: Make sure the agarose dissolves. Wait until it boils and when you are going to transfer the mixture, wear gloves to avoid getting burnt. Transfer the mixture into a removable gel tray.
Add 5 g crushed nutmeg and 50 mL hexane-isopropanol into a flask and warm for 15 minutes.