4.2 Separation Techniques & Assessment of Purity By Grace Ngana
|P3 |You have briefly written up what you did in measuring the melting point in 3rd person past tense. |
Determining the melting point of aspirin
• Firstly we turned on the melting point equipment; we referred to data tables for the actual value for the melting point of the aspirin. • Then we arranged the equipment to a point below the expected melting point we then noted that the rate of heating will influence the reading of the melting point. • Afterward we dipped the sealed capillary tube provided into the sample of our aspirin prepared until we got sufficient depth (about few mm) of the sample contained in the tube. • Further more we gently tapped the tube to allow the solid to fall to the bottom. • Then we placed the sample tube into the hole next to the thermometer in the melting point equipment. • We observed the melting of the aspirin sample through the magnifying glass. • At the point when the compound began to melt, we recorded the temperature using a thermometer. • When the melting was complete, we recorded the final thermometer reading this was the full temperature range of the melting point. • Finally we compared our results to the known data values. |P3 |You have briefly written up what you did in the titration of river water in 3rd person past tense. |
Titration to test the purity of water, by determining the concentration of HCl in the water.
• Using a pipette and pipette filler, we accurately pipetted 25 cm3 of 0.010 mol dm-3 sodium hydroxide solution into a conical flask. • Then we added a few drops of methyl orange indicator and placed it on the white tile. This solution was then titrated with the water obtained from the river. • After we stood the burrette up using a stand and clamp. • We then filled up the burrette to approximately the 0.00 mark with the river water provided...
Please join StudyMode to read the full document