Sodium hydroxide was again drawn up using the pipette, to above the graduation mark, where the meniscus was allowed to fall until the bottom of it was rested on the graduation mark when viewed at eye level. 6. The sodium hydroxide was then run from the pipette into a conical flask where after all the liquid had run out, the tip of the pipette was touched against the bottom of the flask and withdrawn soon after. This was then repeated with the second conical flask. 7.
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.
The buret had used the NaOH thoroughly rinsed three times because at the first titration the NaOH solution was used. About 50Ml the NaOH solution was in a clean beaker and brought it to experiment area. A funnel was used to fill the NaOH into the buret and recorded the initial volume on the buret to the correct number of significant figures. A pipette was used to take 10.00ml HCl into a clean 50mL Erlenmeyer flask. Three drops of phenolphthalein indicator was added into the HCl solution.
The second experiment, procedure 1, combined [Co(NH3)5 (H2O)]Cl2 (0.0060M, 1.52g) and (25mL) of distilled water to an 125mL Erlenmeyer flask. The flask was gently heated (dial 5-6) and stirred until all the compound was dissolved. The heated solution was then vacuum filtered through a fritted funnel and the filtrate was cooled in an ice bath until the
The pipette was then filled with 25.0mL’s of acetic acid and then drained into a conical flask, to speed up the process both of the conical flasks were filled with 25.0mL of the acetic acid. 8. Three drops of phenolphthalein was then added to the flask with the acetic acid. 9. The conical flask was then positioned to just under the burettes dropper which had its stopcock opened to allow a medium drip rate and had the sheet of filter paper slipped under it so that the colour could be seen more earily.
2. A 250mL volumetric flask was washed three times with distilled water. 3. A funnel was used to wash the crystals in to the volumetric flask with the aid of the glass rod and the wash bottle. All the washings were placed into the volumetric flask.
Materials * Blood smear (On the slide with having well-feathered edge.) * Alcohol Acetone (Fixative solution) * Eosin solution (fluorescent red dye) * New methylene blue (Organic staining agent) * Staining rack (To place solutions) * Bottled or running water (To rinse excessive solutions) * Absorbent paper (To remove or absorb excessive solutions) Steps of the procedure 1. Dip the slide into the alcohol acetone 3-5 times as the speed of second and remove the excessive solution with a paper towel. 2. Dip the slide into Eosin solution for 7 times and remove the excessive solution with a paper towel.
Three tests will then be performed to examine the identity and purity of the synthesized aspirin. The first test will detect the presence of leftover salicylic acid in the synthesized aspirin. The second test uses melting point to evaluate the purity of the aspirin product. A compound that contains impurities will tend to melt over a range of temperatures and at temperatures lower than the fixed mp for the pure compound. The third test will utilize thin layer chromatography to evaluate the purity of the aspirin as well as testing for the presence of leftover salicylic acid or other by products of the reactions.
Using the Primary method used to standardize the concentration of HCl, this will bring much lower percent error in the Ksp For this standardization sodium carbonate should be used for determining the amount of hydroxide in the solution. For this the equation used will be Na2CO3+2 HCl→H2O+2 NaCl The third part of this experiment uses the prepared saturated solution from part one. This part used the value for exact concentration of the HCl. Part three is done to determine the concentration of hydroxide in the solution, allowing the students to determine a value of Ksp for Ca(OH)2 completing the lab. The equation used for part three is: 2
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.