Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
Microcalorimetry experiment was performed on Setaram−C80 heat flow calorimeter coupled to a multiport high-vacuum homemade glass manifold. A specific amount of the sample (approx. 500 mg) was taken into a sample cell, reference cell was taken as empty and together they are connected with Pyrex tee. The sample was heated from room temperature to 200°C under vacuum and kept for 2 h, then 3-4 doses of helium gas were introduced into the system to remove any excess residue such as moisture or organic impurity from the system. The system was heated for 4-5 hr under vacuum at 200°C and then cooled down to the temperature (50°C) where we want to perform the adsorption study.
Mixture is gently swirled and drained out into an Erlenmeyer flask. Anhydrous magnesium sulfate is added to dehydrate the washed mixture. The solution is then filter into a weighed, dry, 100mL Erlenmeyer flask. Dichloromethane in the mixture is vaporized with a rotary evaporator. The Caffeine, white powder residue, (0.0486g) should be obtained.
After the effervescence, (15mL) of concentrated HCl was added drop wise to the solution. The mixture was then heated for 15 minutes in a boiling water bath. In two separate small beakers (20mL) of distilled water was placed in one and (20mL) of 6M HCl in the other. Both beakers were placed into an ice bath. After heating, the mixture was cooled to room temperature and filtered by vacuum filtration into a fritted funnel to yield a purple product.
Fill a 10 mL graduated cylinder with ≈ 7mL if water c. Fill a 1000 mL beaker with ≈ 750 mL of water d. Invert the graduated cylinder into the beaker. Add water to the beaker to completely submerge cylinder. e. Measure the difference between the height of the water in the graduated cylinder and the height of the water in the beaker. f. g. Record the barometric pressure in mmHg. Heat the water via Bunsen burner to 80°C.
Materials: 250mL Beaker Test Tube Calorimeter Burner, Ring Stand, and Wire Gauze Thermometer Balance Procedure: 1. Prepare an appropriate data table. 2. Fill the 250mL beaker about half full. Place it on the stand and begin heating it to the boiling point (100 degrees Celsius).
Then by writing a balanced chemical equation and using the titration formula, Nb+Ma+Va=Na+MbVb , the molarity is able to be determined. Procedure: 1) Using the graduated cylinder add 10.0 mL of water into the Erlenmeyer flask. 2) Add 5.0 mL of HCl into the flask using another graduated cylinder because acid goes into water when mixing them. 3) Add three drops of phenolphthalein indicator into the flask. 4) Swirl the flask in circular movements to mix the substances.
Now right-click on the flask, and select Heating Mantel from Distillation Equipment then, Right-click on the flask, and select Distillation Head from Distillation Equipment last, Right-click on the flask, and select Condenser from Distillation Equipment. Now, right-click on the flask, and select Distillation Take-off from Distillation Equipment. From the Equipment menu, select the 100 mL Graduated Cylinder. Place it under the end of the distillation take-off. The graduated cylinder will collect the distillate.
Gravimetric Determination of Sulfate Purpose The purpose of this lab is to determine the percentage of sulfate in the hydrate by precipitating the sulfate as barium sulfate. Materials Filler paper Sodium sulfate Graduated cylinder Bunsen burner Watch glass Beakers (250 mL, 400 mL) Rubber bulb Graduated pipette Beaker tongs Funnel Filter Paper Sodium Sulfate Drying oven Wash bottle Stirring rod Silver nitrate Hydrochloric acid Distilled water Small test tube Procedures First, .4861 grams of sodium sulfate was placed into a clean 400mL beaker. Exactly 200mL of water and 1mL of HCl was added to the same beaker. A watch glass was placed on the beaker and the solution was heated using the Bunsen burner to a gentle boil. The watch glass was removed with the beaker tongs.
Calculate the exact normality of Na2S2O3 knowing that in this chemical reaction 1 gram-equivalent of K2Cr2O7 react with 1 gram-equivalent of Na2S2O3 (1 mole K2Cr2O7 react with 6 moles Na2S2O3). Determination of peroxide value. Weigh 3.00 g oil (with precision of 0.001 g) into a 250 ml Erlenmeyer flask. Add 10 ml chloroform and swirl to dissolve oil. Add 15 ml acetic acid,