Graduated cylinders, and mL Hot pad or oven mitts Hot plate Lab notebook Timer Scale capable of measuring in grams; needed if the Sodium chloride is in solid rather than liquid form Clear plastic cups 3 Disclaimer:
Salicylic acid 2-Hydroxybenzoic acid Chemists made sodium salicylate for doctors to try on patients. It was found to have fewer digestive side-effects, and still worked to reduce pain, however it tasted horrible and caused rheumatism patients to vomit.
Tell us what you need to have done now! In Kolbe synthesis, a common industrial method of manufacturing salicylic acid for aspirin, sodium phenoxide is heated under pressure with carbon dioxide.
The reaction mixture is then acidified to produce salicylic acid. This enables autocatalysis to occur; the hydrolysis of esters is catalysed by acids, and both products are acids. Hence hydrolysis is slow to start with before accelerating as more hydrogen ions are produced Use in medicine: They do this by irreversibly inhibiting cyclooxygenase enzymes which produce prostaglandins and thromboxane.
This is why aspirin is commonly used for relief from headaches, muscular pains, arthritis and menstrual pain. It is also used to reduce the risk of heart attacks and strokes due to thromboxane stimulating the clotting of platelets.
A prostaglandin A thromboxane In commercial aspirin products, a small amount about mg of acetylsalicylic acid is bound together with a starch binder and sometimes buffers and caffeine to form a tablet.
In the small intestine, the acetylsalicylic acid is broken down to give salicylic acid, which is absorbed by the bloodstream. The function of the buffer is to reduce any irritation that might be cause by the carboxylic acid group of the aspirin. Choosing methods of composition analysis Thin layer chromatography is one method of separating and identifying aspirin.
The procedure is carried out by placing small amounts of synthesised product, salicylic acid and commercialised aspirin, on one edge of a chromatography plate. When placed in a container with the solvent, the solvent will flow up the chromamtogram carrying the samples with it.
The differing solubilities of each sample in the solvent means that they will travel a different distance up the plate more soluble will move higher, more attracted to the plate will remain nearer to the line.
UV light will then be used to detect the aspirin after removing the plate. Another unsuitable option of analysis is by melting points. I will not use this method because it requires the removal of all starch, silica and cellulose from the tablets.
Many processes such as suction filtration and crystallisation would be required just to isolate the aspirin. It would therefore not be a worthwhile method in the time allowed.
Both of these factors mean that the method is unlikely to be successful. A more suitable method is back titration. This is likely to be reliable due to taking into account the fact that an impurity in aspirin is salicylic acid, making it accurate.
In this way it is a better method to standard titration see precursors of back titration Colorimetry would be a good method for comparison with back titration, as the two are very different.
The back titration requires alkaline hydrolysis of the aspirin, whereas colorimetry requires several separate samples undergoing acid hydrolysis. Colorimetry will directly measure the concentration of salicylic acid in a hydrolysed aspirin solution, whereas back titration calculates the initial amount of aspirin present via a method of differences.
Another advantage to the colorimetry is that it requires little apparatus, so is a suitable method under the given conditions and time restraints.
Back titration Alkaline hydrolysis 7 Aspirin undergoes very weak hydrolysis, due to one aspirin molecule reacting with 2 OH ions.
To overcome this, a known excess of base is added to the sample solution. A titration is then carried out with hydrochloric acid to find out the amount of unreacted base. A simple subtraction will then indicate the amount of base which has reacted with the aspirin, and thus the amount of aspirin in the sample.Nov 30, · In this video, we explore how we determine the purity of a chemical, using water as as example.
We then look at what is meant by a formulation.
GCSE Science Chemistry () Purity . In this science fair project, you will compare the size and shape of crystals grown in three different temperature conditions: room temperature, in the refrigerator, and in an ice bath.
With just water and borax, a household cleaning product, you can discover the best recrystallization method for growing large, pure crystals. This project demonstrates several chemical processes, yet the materials are easy to find and the science is safe enough for kids. Make Homemade Invisible Ink You can use invisible ink or disappearing ink to write secret messages.
O Level Chemistry; Contact; Percentage Yield & Percentage Purity. Show/Hide Sub-topics (O Level) The quantity of product that is calculated to be produced when the entire limiting reactant is used up is called the theoretical yield.
The quantity of product that is actually. Purity of Aspirin Objectives - To research, using various sources, the history of aspirin, its use in medicine, methods of synthesizing it and of measuring its purity. The Chemistry of Clean: Make Your Own Soap to Study Soap Synthesis such as lye.
In this chemistry science project, you will carry out the chemical steps needed to transform coconut oil into a usable bar of soap, and purify it with salt to measure how its pH changes with its purity. You will track the purity of the soap by measuring its.