Theory: The acid value can be defined as the number of milligrams of potassium hydroxide required to neutralize the free fatty acids present in one gram of fat. It tells about the measure of rancidity as free fatty acids are normally formed by the decomposition of oil glycerides. The acid value is expressed as percent of oleic acid, lauric or palmitic acid. Principle: The determination of acid value is based on the principle of directly titrating the oil in an alcoholic medium against potassium hydroxide or sodium hydroxide solution. Analytical importance: The value is the relative measure of the amount of fatty acids that have been liberated due to the hydrolysis of the glycerides as a result of action of moisture, temperature and/or lypolytic enzyme lipase.
Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator. The concentrated extract was then passed through a chromatographic column (30 cm x 10 mm i.d) containing 2 g florisil (lower) and 1 g sodium sulphate (upper) which is pre wetted with hexane: acetone (1:1). OCPs were eluted with 25 ml hexane: acetone (1:1).The solvent was evaporated using rotary evaporator and final volume was adjusted to 5 ml, which is used for GC analysis. All the sediments were analyzed for HCH and
The solution were tested by using calibrated pH meter to get the pH value of the solution. Results and Discussions pH ratio between acid and base: 7.3 = 6.82 + x x = 0.48 0.48 = log ([base])/([acid]) 100.48 =base/acid salt/acid = 3.02 There, 1 acid : 3 base calculate number of mole of acid and base to find the mass : molar = mol/L 50 mM = (mol )/(0.5 L) mol = 25 mol number of mole of NaH2PO4 25/4 = acid = 6.25 mol number of mole of Na2HPO4 25/4 × 3 = salt = 18.75 mol to calculate the mass of the acid and base : Mass of NaH2PO4 (6.25 mol)/(119.98 g/mol)=0.052g Mass of Na2HPO4 (18.75 mol)/(141.96
To make the 2M HCl solution, 200mL deionized water was added to a 600mL beaker labelled “2M HCl” by using a graduated cylinder. Then, 100mL 6M HCl was added to the same beaker also by using a graduated cylinder. The solution was stirred with a stirring rod. To make the 2M NaOH solution, 50mL deionized water was added to a 400mL beaker labelled “2M NaOH”. Then, 100mL 3M NaOH was added to the same beaker.
Each grounded drug tabled was transferred into a test tube using a spatula. Each test tube was labeled as Tylenol or Anacin. A 2.5ml of 50:50 mixtures of the methylene chloride and ethanol was added to each test tube. The content of each test tube was thoroughly stirred using a glass rod to ensure maximum extraction. The developing chamber for the TLC plates was prepared by adding ethyl acetate that contained 0.5% acetic acid to the glass jar.
First, 50 mL of the sample was placed into a 250 mL Erlenmeyer flask, and onto a stirring plate. Then, the pH of the solution was measured and adjusted to be within the range of 4 and 6, using nitric acid and sodium hydroxide. After the pH was optimal for the experiment, a single mL of indicator- acidifier reagent was added to the sample. Then, 50 mL of mercuric nitrate was place into a burette and titrated with the sample until the color of the solution turned from blue to purple. The volume of titrant used for the reaction to reach endpoint was recorded.
• Hydrogen peroxide (H2O2, 2mM) in phosphate buffer (3.0ml) was taken in an experimental cuvette, followed by the rapid addition of 40μl of enzyme extract and mixed thoroughly. • The time required for a decrease in absorbance by 0.05 units was recorded at 240nm in a spectrophotometer (Genesys 10-S, USA). • The enzyme solution containing H2O2-free phosphate buffer
The purpose of this experiment was to perform a Wittig reaction using two different methods: In method I, 250 mg aldehyde was mixed with 785 mg phosphonium salt in 5 M NaOH solvent. This mixture was stirred for thirty minutes and filter by vacuum filtration for the product. In method 2, 250 mg of aldehyde, 785 mg, benzyltriphenylphosphonium chloride, and 380 mg potassium phosphate tribasic were homogenize with a pestle and mortar. Vacuum filtration was also used in this method to attain the product. The products in both methods were used for recrystallization and TLC.
Ltd. 4 Melting point Sentwin India 5 NMR Bruker Advance II 400MHz 7 Heating Mantle Inco 6 Structure builder Chem draw Ultra 8.0 4.2 Experimental work: 4.2.1 General procedure for Chalcones: 2’-hydroxy acetophenone or 2’-hydroxy propiophenone (0.2ml) and substituted benzaldehydes (0.5 g) were mixed in the round bottom flask. After that 40% NaOH solution (4g NaOH in 10 ml of distilled water) and ethanol were added in round bottom flask. The reaction mixture was stirred upto 6-48 hours. Completion of reaction was monitored in TLC plate (n-Hexane: Ethyl acetate 9:1). The reaction mixture was poured into ice cold water acidify with 1% HCl and precipitates were collected, filtered and dried and recrystalized with ethanol.
The concentration of ethanoic acid in the vinegar can be determined through stoichiometric calculations, Using the values obtained from the titration, and also the chemical equation as a reference. Phenolphthalein indicator is used in this acid-base titration Equipment and materials: Commercial vinegar, Yamaha brand 0.1 mol/dm3, NaOH soloution Phenolpthalein indicator soloution (50.00 ± 0.5 cm3 ) cm3 burrete (250.00 ± 0.5 cm3) volumetric flask a (250 cm3± 0.5 cm3)
The purpose of this experiment was to create two 40 mL buffers and evaluate its buffer capacity at pH 4. To do this, buffer #1 consisted of the mixture of 0.5003 M acetic acid and .50 M sodium acetate, while buffer #2 consisted of the mixture .5003 M acetic acid and .4289 M NaOH. Within each mixture, there is a ratio of conjugate acid to conjugate base. By using the Henderson Hasselbalch equation, the volume for the base and acid to buffer the pH of solution at 4.0 were calculated. Two titration were performed for each buffer: HCl and NaOH.