Three drops of phenolphthalein indicator was added into the HCl solution. The stopcock was opened and the NaOH solution was added into the HCl solution. The flask was swirled to mix the solutions and titrate to a faint pink end point. Recorded the final volume on the butret and used the final volume as a beginning volume to repeat the titration. At the second titration, the experiment was exactly the same as the first titration but the H2SO4 solution was used to instead of the HCl solution.
When the liquid above the precipitate was clear, the solution was tested for completeness of precipitation when a few drops of BaCl2 solution were added from a pipette. Next, filter paper was place into the funnel and streamed with distilled water. A clean 400mL beaker is placed under the funnel and the precipitate was filtered through. When all the precipitate was filtered and removed from the beaker the residue is washed with distilled water. About 3mL of the wash water is collected in a small test tube.
Once all the equipment has be gather, step one was to clean the flask because a dirty flask might have an effect on the precise mass of it. To clean the flask, I used distilled water but before I used the water, I had to get the temperature of the water by using a Thermometer according to the experiment guidelines. After getting the temperature, I used the water to clean and then I air dried it. The next side was to weight the empty flask in record the numbers on a weighted scale. After recording the empty flask, I placed the
Once it is completely distilled, remove your filtered material and add 2 mL of dichloromethane. Swish the flask, and then place into a small beaker. Next, place the beaker with the distilled liquid on a heating mantle and heat to a gel like substance. Make sure not to burn it. The next processes that will be
- Make sure the Compounds are no where close to your other sensory organs, remember that only your eyes are protected by the Goggles. -If a compound is spilled, wipe it up immediately and tell the instructor. Materials : powder forms of these compounds - LiNO3 - NaNO3 - KNO3 - Ca(NO3)2 - Ba(NO3)2 - - Unknown compound A - Unknown compound B - Goggles, Bunsen burner, distilled water, Q-tips, paper towel and a striker. Procedures 1- Turn on the Bunsen burner around the 45 degree angle. 2- Feel the gas on the top of the Bunsen burner with your hands, adjust if too high or too low.
The first part involved testing the indicator. This was done by preparing a buffer solution, dipping a few grains of EBT powder into the solution, and checking to ensure that the resulting solution turned a bright, clear blue. The second part involved actually performing the titration. In this step, I simply constructed a mechanism that would hold the titrator and I dripped a few drops of EDTA solution from the titrator into the beaker. Finally, the last step involved titrating the water.
While the soil is soaking, add dispersing agent into the control cylinder (Sodium Hexametaphosphate 125ml) and fill it with water to the mark. 3. Shake the cylinder in such a way that the contents are mixed thoroughly. Insert the hydrometer and thermometer into the control cylinder and record temperature. 4.
Look in the water bath on your table for a flask labeled DMA. This flask contains Davis Minimal Agar that has been autoclaved to make it sterile, and is being kept at 47 C to keep it liquefied. 3. Think about these important points in pouring a petri plate before doing it: a) You must work quickly, because once the container of minimal agar is removed from the bath, it will start to harden within 2-3 minutes. b) When pouring agar into the petri dish, pour just enough to fill the dish about half way.
* Then you will have to put the test tube in a water bath and leave it until the contents reach the same temperature as the water bath. * Then you will have to take the thermometer from the test tube and put a glass rod into it instead. * After this you will have to use a 2cm syringe to measure out 1cm of lipase to the beaker in the water for the temperature you are investigating. * Then add the lipase to the test
Keep swirling the solution until a pink color is visible throughout from the phenolphthalein. 8) If over titration occurs ask the teacher for further instruction. 9) Write down the final volume in the NaOH buret 10) Subtract the final volume of NaOH from the initial volume. 11) Repeat this process at least twice more. Materials: * Buret (50mL) * Graduated Cylinder (10mL) * Beakers (250mL) * Buret stand * Erlenmeyer flask (125mL) * Safety goggles * Buret clamp * 0.10M HCl (aq) (25.0mL) * NaOH (aq) Vocab: * Standard Solution: a solution containing a precisely known concentration *