• Carefully decant the solvent solution from the drying agent through the funnel into the flask. Rinse the Erlenmeyer flask with about 10 ml of solvent and pour the solvent through the funnel, too. Remove the funnel, add two or three boiling chips and reattach the thermometer and adapter to the still pot. • Discard the magnesium sulfate remaining in the Erlenmeyer flask by dissolving it in tap water and pouring the solution down the drain. • Before beginning the distillation, weigh a clean, dry 1 narrow mouth screw cap bottle on a balance.
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
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
10- Transfer the ester layer to a small dry test tube and dry the ester with anhydrous CaCl2 and stir for 10 min. 11- put it in a preweighed dry round bottom flask . 14- Determine the yield, refractive index, and % yield of ester. Conditions :- 1) This reaction is catalyzed by acid, Like Fischer esterification. 2) Usage of water in step (5):So that after Estrification is completed , any excess unreacted acetic anhydride is hydrolyzed.
3) Centrifuged at 2500 rpm for 12 mins. Upper hexane layer (supernatant) was transferred carefully into another test tube. 4) Evaporated the hexane under a stream of grade 1 nitrogen gas and added 100 µl of methanol to the residue left and vortexed for 1 min. 5) Injected 100 µl of extract in HPLC vials and closed properly. Standard curves and calculations- Retinol was quantified from standard curves peak area for each vitamin.
Formula 2: % Component= 100% component mass (g) sample mass (g) Procedure First, we measured out the evaporating dish to find the mass. Then we added around 3 grams of our sample (2.832g exactly). Next we added the isopropyl alcohol to dissolve the Benzoic Acid. We filled the evaporating dish, stirred, and then decanted the sample into a 140mL beaker with a stirring rod. This
Experiment 9: The Molar Volume of a Gas Introduction Description: The purpose of this experiment was to determine the molar volume of a gas by conducting the hydrogen gas producing chemical reaction: Mg(s)+2HCl (aq)→〖MgCl〗_2 (aq)+H_2 (g) A known mass of solid magnesium was reacted with an excess of hydrochloric acid in a sealed vessel, three times, for a total of three trials. A gas pressure sensor and temperature probe were connected to the vessel and a computer which allowed Logger Pro to collect the pressure and temperature change data through the course of the reaction. This data was then used to calculate the molar volume of the hydrogen gas at STP, and the Universal Gas Constant, R, for each trial. Background: STP stands for
The mineral sample was rinsed with distilled water and filtered into a volumetric flask (50 mL). (Some errors occurred at this portion of the experiment, because the funnel was too close to the flask. No solution could filter through until it was lifted. When lifted, some solution spilled.) Next 15M NH4OH “ammonium hydroxide” (4mL) was added to the volumetric flask.
Ensure that solid is completely dissolved using a stirring rod. Next, a 10 mL beaker is filled with 3 mL of HCl and measure 10 mL of ionized water into a 140 mL beaker. Carefully turn on laboratory burner and start cleaning the Nichrome wire by dipping it into concentrated HCl acid. Hold the Nichrome wire on top of the flame and repeat the step until the wire doesn 't show any color. When the wire is clean, dip the wire again with some of the acid and dip it into the solution with the unknown compound in it.
32 100 μL of afore-prepared sample solution and the mixed reference standard were diluted 100 times with ethyl acetate. 50 μL of these dilution solutions were separated on the TLC plate coated with SNISG. The plate was developed with petroleum ether: ethyl acetate (4:1) and the movement of solvent was usually controlled at 1 cm from the upper edge. After completion, the plate was dried until no solvent smell remained. It was sprayed with an ethanol solution containing 10% sulfuric acid, and heated at an infra-red drier until obvious color came up, as shown in Fig.2 (B.ab).
1. 150 ml of boiled water was poured into each of the three beakers labeled A, B, C. 2. Five tea bags were soaked for the time given by the manufacturer (two minutes) , in beaker A (Control). The teabags were immediately removed after the time elapsed. 3.
Before starting the heating process, measure the weight of the crucible with its cover first and then tare the balance, and after that adding about 1 gram of the sample to the crucible with its cover, and then weigh it. Moreover, it is possible liberating harmful gases during the process of heating; therefore, being careful is important. The heating process ends when this sample changes the color to brown because water of hydration is removed to the sample. Additionally, give time to the small cool down and measure its weight. Next, transfer the sample to a 50 mL beaker and mixes with distilled water, which gets by rinsing the crucible with its cover in 8mL, so the solution is generated.