Vitamin C is sensitive to a variety of factors and can easily degraded; it is considered unstable.3,4 Moreover, in the interest of using …show more content…
A glass stir rod was then used to crush any large chunks, then the stir plate was turned back on for five minutes. During the dissolving process, 250 mL potassium iodate (KIO3) was made from the concentration KIO3 solution made previously in Lab F. Also, a burette was rinsed and filled will 0.01085M sodium thiosulphate. Once the Vitamin C was completely dissolved, is was transferred into a 500mL volumetric flask using gravity filtration; then filled to the line and mixed. To ensure a quantitative transfer, only instruments were rinsed into the flask. Then, a rinsed, 25mL pipette was used to transfer the previously made KIO3 into a 125ml Erlenmeyer flask. Subsequently, using a scoop, approximately 0.2g potassium iodide (KI); along with, using a transfer pipette, 1 mL 1M sulfuric acid (H2SO4). Finally, 10mL of the prepared Vitamin C solution was added to the Erlenmeyer flask and mixed. Sodium thiosulphate was titrated with the solution in the Erlenmeyer flask until a pale, straw-like colour was achieved. This signalled that five drops of starch solution, by means of a plastic pipette, were to be added to the Erlenmeyer flask. To complete the titration, sodium thiosulphate was added until the end point, at which the solution turned clear. This process was repeated five times until the volume titrated thiosulphate were within ±0.2mL. All un-neutralized waste was emptied into a waster beaker, neutralized, then poured down the