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.
3- Add 0.05 moles of concentrated sulphuric acid to round bottom flask very slowly and carefully then put a magnetic stirrer . 4- Set up reflux system using a clean and dry condenser .
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.
⋅ 5H2O, which has about 36.0%, and CuCl2 ⋅5H20 (21.17%). Materials: Ring stand, ring clamp, evaporating dish, Bunsen burner, clay triangle, crucible tongs, electronic balance, sample of hydrated salt. Methods:
The above solution converts of colorless to yellow suspension solution which produced TiO2 nanopowder by drying process at 85°C in anstove for 15 hours. Finally, TiO2 nanopowder obtained were treated in furnace at different temperatures (400°C-800°C) for 2 hours. The initial heating rate was maintained at 5 °C/min. 2.3. Characterization 2.3.1 UV- Visible diffuse reflectance spectroscopy (DRS)
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. Place the wire back into the flame again and observe the color of the flame.
Then the blower was turned on for sufficient duration and UV lights were switched on for one hour. LAF microbial contamination test (Settling plate method) A total of three petri dishes were prepared aseptically inside a laminar air flow (LAF), and then the petri dish was filled by pouring sterile Tryptone Soy Agar (TSA) liquid media and allowed to solidify. One test media was placed in the LAF cabinet, one test media is placed beside the LAF cabinet while the other the test media was placed near the door. The three petri dishes lid were opened and allowed to stand for 15 minutes and closed again.
Purpose The purpose of the experiment was to determine the molar mass of unknown solute number 1. This was done by using colligative properties of solutions specifically, freezing point depression. Colligative properties depend on the number of molecules that are present in the solution rather than the nature of the molecules . This fact is useful because knowing this allows one to use the properties of the number of molecule in the solution without needing to worry too much about the nature of the molecules.
Procedure—Post-dilution 1) Use a pipette to fill 3/4 of each cuvette with the new solution from the beaker. Repeat until you have 4 cuvettes with the same solution. 2) Put a lid on each cuvette in order to prevent
The empty weighing boat was placed into weighing balance and tarred it. 3.2 g of yeast extract, 4.0 g of peptone, 4.0 g of dextrose were weighted and added to the scott bottle that contain distilled water. The solution was mixed and dissolved. The solution was placed into autoclave and has been autoclaved at 121o C for 2 hours. After autoclaved, the solution has been cooled for 10 minutes.