Properties of Acetysalicylic Acid - Lab Report Example

1. Acetysalicylic Acid Aspirin is widely used as an “analgesic” or as “antipyretic”. Usually, people with colds take it to relieve headache, muscle pain, minor ache. It is also prescribed as a mild blood thinner, which is favorable to people who just had a coronary heart bypass. However, aspirin should not be taken after surgery since it can induce hemorrhaging. Reason for such is that it interferes with normal blood clotting. The structure of aspirin is CC(=O)Oc1ccccc1C(=O)O ( Merck Index ). The pka is 3.49. COOH OCOCH3 Acetylsalicylic acid ( aspirin ) 2 )Morphine Source: Opium, Morphine and Heroin. Morphine – when the –OH group is replaced by –OCH3 this becomes produces codeine . But when both the blue and red –OH groups are replaced, the result is heroin. Morphine is considered as the gold standard of analgesics since it is effective in relieving pain. It can relieve deep pain but is not promising for pain resulting from injuries. It has anesthetic properties sans unconsciousness. However, excessive amount of morphine can depress respiratory system. Morphine works by blocking receptor sites that signal pain to the brain. The key to morphine’s efficacy is its shape which fits into the cells. Moreover, morphine acts like natural painkillers such as endorphins. 3) Properties of alcohols and phenols - alcohols and phenols, like water are both weakly basic and weakly acidic - As weak bases, alcohols and phenols are reversibly protonated by strong acids to yield oxonium ions, ROH2 + - as weak acids, alcohols and phenols dissociate to a slight extent in dilute aqueous solution y donating a proton to water, generating H3O + and and alkoxide ion ( RO -) or a phenoxide ion ( A+0 - ) - phenols are about a million times more acidic than alcohols - phenols are soluble in dilute aqueous in dilute aqeous NaOH but alcohols are not -Esters and carboxylic acids are reduced to give primary alcohols -Like alcohols carboxylic acids form strong intermolecular hydrogen bonds 4) Warfarin Warfarin is an anticoagulant, meaning, it acts a s a blood thinner like aspirin. However, warfarin is more potent and can even cause severe hemorrhaging. This is due to the fact that warfarin can decrease coagulation through inhibition of Vitamin K. It is synthetically derived from coumarin, which is extracted from plants such as licorice, lavender and woodruff. Warfarin is commonly used in rat pesticide. Once a cat ingests a mouse that ate warfarin-laced pesticide, the cat’s liver would fail and internal bleeding occurs immediately. However, warfarin has also therapeutic purposes especially in the prevention of thrombosis as well as embolism. 5 ) Partition coefficient and log p Log P oct/wat = log ( (solute ) octanol (Solute ) un-ionized water The partition coefficient is the ratio of concentrations of un-ionized compound between two solutions. To measure : the pH of the aqueous phases is adjusted such that the predominant form of the compound is un-ionized . The logarithm of the ratio of the concentration of the un-ionized solute is the solvent called log P. 6) The three methods for log P determination are: 1. Shake flask or tube method 2. HPLC ( high- performance liquid chromatography) 3. Electrochemical method The shake flask or tube method is the most classical method known by chemist. The process is simple: the solute in question is slowly dissolved in a certain volume of octanol and H2O. Then, a certain method such as UV/VIS spectroscopy is used to measure the amount of concentrated solute in the solvent. This method is known for its accuracy but it is also time-consuming. 7) Bioavailability Bioavailability is a common term in the field of pharmacology. When a drug’s bioavailability is being determined, it meant giving a description of the fraction of a dose of an administered drug that would be assimilated by the blood. Bioavailability is a property of a drug in pharmacokinetic. For example, when a drug is given to a patient intravenously, bioavailability is 100% since it is immediately introduced into the blood. However, when a drug is given orally ( as commonly done) , there is a probability that the efficacy of the drug is reduced. 8) When a drug easily binds to plasma proteins, it is said to be more effective in doing its job. On the contrary, when it easily unbounds, then the drug can diffuse faster. Certain drugs such as warfarin have a high binding property which makes it toxic in high amounts since most of it is easily absorbed by the body. Moreover, the unbound portion ( let’s assume 5% ) is also slowly-released in the body . This does not mean that this is safe. Drugs considered hydrophobic are retained in the body for a longer time which means it would be well metabolized. The danger is that It is for this reason that the industries manufacturing products with chemicals are careful in analyzing the content of their products. 9) The mechanism of action ( MOA ) is an important biochemical interaction that highly determines the drug substance effect. Small drugs upon entering the body have specific targets to which it binds. Usually, the targets of these drugs are enzymes or receptors . For example, antihistamines, drugs used to treat allergies. The formula of which is C22H23CIN2O2. Antihistamines specific targets are peripheral histamine H1 receptors . Another example would be aspirin. The main function of aspirin is to cause irreversible inhibition of an enzyme- cylcooxygenase. When this enzyme is controlled, prostaglandins and thromboxanes are not produced. The result of which is less pain and inflammation. Cylcooxygenase is an enzyme responsible for producing prostaglandins as well as throboxane which are known as biological mediators. Prostaglandins are found in all tissues of the body and when produced by the body, they produce several reactions or stimuli like inflammation. .10) Partition hypothesis is a theory that predicts that drugs or substances that are weakly acidic ( i.e. antihistamines ) are more absorbed by the stomach than the small intestine. Thus, the acidic drug when ionized will not diffuse well in such environment . And when the body starts to absorb the basic drugs from the small intestine rather than from the stomach, a delay happens since ingested drugs must still pass through the stomach. It takes time for the drug to partition in the bloodstream so the person must anticipate this delay and drink the medicine earlier. 11)Percent ionization at ph4 -99.9, Ph7 -90 ,at ph9 -10 percent 12. a. 33% b. 20% 13. 1500 mL x 0.16 moles = 0.24 1000ml pH = -log [ H+ ] pH = - ( log 0.24 ) pH = - ( - .620) pH =.620 14. 25mL x 0.50 moles 1000ml = 0.0125 75 mL x 0.50 moles = 0.0375 1000 ml HC2H3O2 H+ + C2H302 - .0375 1.8 x 10 -5 0.0125 [ H+ ] = (1.8 x 10 -5 ) (0 .0375) 0.0125 [ H+ ] = 5.4 x 10 -5 pH = - log [ H+ ] pH = - ( log 5.4 x 10 -5 ) pH = - ( -4.27 ) pH = 4.27 N = 1 x 14 = 14 4g x 1mole =0.235 15. NH3 H = 3 x 1 = 3_ 17g mol. 17 N = 1 x 14 = 14 8g x 1 mol. = 0.151 mol. 53g NH4Cl H = 4 x 1 = 4 Cl = 1 x 35 = 35 53 0.235 = 0.94 0.25 0.151 = 0.604 0.25 ( 5.6 x 10 -10 ) ( 0.604 ) = 3.60 x 10 -10 0.94 pH = -log [ H+ ] pH = - ( log 3.60 x 10 -10) pH = - ( -9.44 ) pH = 9.44 16. HC2H3O2 H+ + C2H302 - 1.0 1.0 pH = - log ( OH ) -log( OH )= -pH OH =- pH OH =antilog 0.9 x antilog -6 OH = 7.94 x 10 -6 M or 7.94 x 10 -6 moles /L 17. pH = -log [ H+ ] log [ H+ ] = -pH log [ H+ ] = -7.71 [ H+ ]= antilog 0.29 x antilog -8 [ H+ ]= 1.95 x 10-8 ≈ 2 HClO Ratio : 3.5 x 10-8 ≈ 4 Ratio : HClO : ClO 4 : 2 Or 2: 1 18. HC2H302 H+ + C2H3O2 – 20 mL x 0.20 moles = .004 1000 ml 50 mL x 0.11 moles = .0055 1000 ml [ H+] [ C2H3O2 - ] = 5.6 x 10-10 HC2H3O2 Read More