Measurement of lipid peroxidation TBARS, a measure of lipid per oxidation, was measured as described by Ohkawa . Briefly, 1 ml of suspension medium was taken from the 10% tissue homogenate. 0.5 ml of 30% Trichloroacetic acid (TCA) was added to it, followed by 0.5 ml of 0.8% thiobarbituric acid (TBA) reagent. The tubes were covered with aluminium foil and kept in shaking water bath for 30 minutes at 80°C. After 30 minutes, tubes were taken out and kept in ice-cold water for 30 minutes.
Upon finding the actual concentrations of salicylic acid, concentration of aspirin in the flask at various times can be found using the equation [aspirin]t = [aspirin]0 – [salicylic acid], since at constant volume, number of moles of initial aspirin decrease to form salicylic acid. Initial concentration of aspirin formed as follows: [aspirin]0 = 0.212g / (180.157gmol-1 * 50/1000 L) = 0.0235 mol L-1. Thus using the first test as sample, [aspirin]t = 0.0235 – 9.981*10-4 = 0.0225 mol L-1. To find the rate constant, we will need to log the value of [aspirin]t and plot it against time to find the rate constant. Figure 1 shows the diluted and actual concentrations of salicylic acid, the concentration and log value of aspirin at various times.
Twenty tablets were weighed accurately and powdered. An amount of the powder equivalent to 5 mg of amoxicillin trihydrate (content of one tablet) was dissolved in 60 ml of diluent. The solution was stirred for 10 min using a magnetic stirrer and filtered into a 100 ml volumetric flask through 0.45µ nylon membrane filter. The residue was washed 3 times with 10 ml of diluent and then the volume was completed to 100 ml with the same solvent. This solution was diluted with diluents to gae a concentration of 0.1 mg/ml solution each of Amoxicillin trihydrate.
In this experiment, racemic 2-methylcyclohexanone was reduced using sodium borohydride as a nucleophile to give a diastereomeric mixture of cis and trans secondary alcohols. The products were analyzed for purity using IR spectroscopy and gas chromatography. 1.2 g of 2-methylcyclohexanone and 10 mL of methanol were combined in a flask and cooled in an ice bath. Two 100 mg portions of sodium borohydride were added to the flask and stirred. 5 mL of 3M sodium hydroxide, 5 mL of de-ionized water, and 15 mL of hexane were added to the reaction flask and stirred.
Linoleic acid peroxidation was initiated by the addition of 4 mM FeSO4.7H2O, incubated for 60 min at 37oC and terminated by the addition of 2 mL of ice cold trichloroacetic acid (10% v/v). An amount of 1 mL of thiobarbituric acid (1% w/v in 50 mM NaOH) was added to 1 mL of the reaction mixture, followed by heating at 95oC for 60 min. The reaction sample was read at 532 nm.7 The percentage of linoleic acid peroxidation inhibition activity was calculated using the following equation: % Inhibition = [(AB - AA)/AB] x 100, where AB, absorption of blank sample, AA, absorption of test sample. 2.5.4. Metal chelating activity Briefly, 2 mM FeCl2 was added to different concentrations of test sample and reaction was initiated by the addition of 5 mM ferrozine.
91.5 lb/72 (molar mass of FeO)) ∴Selectivity of Fe=(10.714 moles Fe)/(1.271 moles FeO)=8.43 (mole Fe)⁄(mole FeO) Example 3.6: Chemical Equation and Stoichiometry Question A common method used in manufacturing sodium hypochlorite bleach is by the reaction: Cl_2+2NaOH→NaCl+NaOCl+H_2 O Chlorine gas is bubbled through an aqueous solution of sodium hydroxide, after which the desired product is separated from the sodium chloride (a by-product of the reaction). An aqueous solution of NaOH containing 520.45 kg of pure NaOH is reacted with 386.82 kg of gaseous chlorine to give 280.91 kg of NaOCl. (a) What was the limiting reactant? (b) What was the percentage excess of the excess reactant used? (c) What is the degree of completion of the reaction, expressed as the moles of NaOCl formed to the moles NaOCl that would have formed if the reaction had gone to completion?
From the bromination of 0.05g aniline, 0.156g of the product was collected. The percent yield was calculated to be 88.1%. Some amount of the product was lost when transferring the product from the Buchner funnel to the balance to measure its mass. To ensure the formation of the desired product, melting point of the product was measured to be 119.8-121.90c, which is in the range of the normal melting point of 2,4,6-tribromoanilne, 120-1220c. Thus, the product was indeed
1.00 gram of fine white salicylic acid powder was weighed in a clean, dry 125mL Erlenmeyer flask. 3mL of strong smelling, clear colorless acetic anhydride liquid was then measured in a 10mL graduated cylinder in the fume hood, and poured into the Erlenmeyer flask. The flask was then gently swirled while 5 drops of 85% phosphoric acid was added to the flask. During this time, the solution in the flask was whitish and cloudy. Phosphoric acid was used in the synthesis to become a source of H+ ions that would catalyze the reaction.
The reaction was started by adding 0.1 ml of the crude extract to 0.5 ml of the reaction mixture, which contained 7 mm MgCl2, 5 mm Na2MoO4, 2mm Na2-ATP and 0.032 U ml-1 of sulphate-free inorganic pyrophosphate in 80 mm Tris–HCl buffer (pH 8.0). Another aliquot from the same extract was added to the
The residual biomass was separated by filtration and washed with distilled water. For alginate extraction, the acidified algal biomass was suspended in 3% Na2CO3 solution at different alkali: alga ratio (20, 40, and 60 mL/g). The different extraction temperatures ranged from 25 to 45º C, and lasted for 1 to 3 h. For each experimental run, sodium alginate was collected by filtration and precipitated with absolute ethanol (1:2 v/v). The mixture was maintained at 4º C overnight. The precipitate was collected by vacuum filtration and allowed to dry at room temperature.