What is the principle of titration of aspirin?
Aspirin is a weak acid that also undergoes slow hydrolysis; i.e., each aspirin molecule reacts with two hydroxide ions. To overcome this problem, a known excess amount of base is added to the sample solution and an HCl titration is carried out to determine the amount of unreacted base.
Which reaction mechanism explains the synthesis of aspirin?
The synthesis of aspirin is classified as an esterification reaction. Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid’s hydroxyl group into an ester group (R-OH → R-OCOCH3).
What is mechanism of action of aspirin?
Aspirin is non-selective and irreversibly inhibits both forms (but is weakly more selective for COX-1). It does so by acetylating the hydroxyl of a serine residue. Normally COX produces prostaglandins, most of which are pro-inflammatory, and thromboxanes, which promote clotting.
What is the role of ethanol in assay of aspirin?
water — the ethanol helps the aspirin dissolve. Note that an aspirin tablet contains other compounds in addition to aspirin. The aspirin/NaOH acid-base reaction consumes one mole of hydroxide per mole of aspirin.
What is the formula of aspirin?
Why is aspirin banned?
NEW DELHI: The Delhi government on Tuesday banned without-prescription sale of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, disprin, brufen and voveran because of the danger these drugs pose to dengue patients.
What are the 4 therapeutic effects of aspirin?
Aspirin can relieve mild to moderate pain, swelling, or both associated with many health issues, such as:
- a cold or flu.
- sprains and strains.
- menstrual cramps.
- long-term conditions, such as arthritis and migraine.
Is aspirin an acid or base?
Aspirin itself is an acidic medicine and causes gastric irritation and regurgitation which can lead to low oral pH levels .
What is the pH of aspirin?
Aspirin (acetylsalicylic acid) has a pKa of 2.97 Calculate the percentage of aspirin (acetylsalicylic acid) available for absorption in the stomach (pH = 2.0) and in the duodenum at (pH = 4.5).
Why do you need to titrate an aspirin sample?
Second, you will titrate a sample of your aspirin (acetylsalicylic acid) with the standardized NaOH to determine the moles of acid in a given weight of your product. This will allow you to assess its purity. Assuming the aspirin is not contaminated with other acids, the titration allows you to quantitatively determine the purity of your aspirin.
How is the molecular weight of aspirin determined?
Aspirin is prepared by chemical synthesis from salicylic acid, through acetylation with acetic anhydride. The molecular weight of aspirin is 180.16g/mol.
How can I determine the amount of aspirin in a flask?
To each flask, add 20 mL of ethanol (measure by graduated cylinder) and three drops of phenolphthalein indicator. Swirl gently to dissolve. (Aspirin is not very soluble in water — the ethanol helps the aspirin dissolve. Note that an aspirin tablet contains other compounds in addition to aspirin.
Which is the limiting reactant of aspirin equation?
The limiting reactant of the equation was salicylic acid. After the limiting reactant was determined, the theoretical yield of aspirin was calculated at approximately 1.97g. The actual yield was only around 0.67g, producing a percent yield of 34.3%.