Question

please can you answer questions part one

Vitamin C can be measured using a technique called titration. Because vitamin C is easily oxidized, we can use this chemical reactivity to detect it in solution. If we react vitamin C with iodine, the vitamin C is oxidized and the iodine is reduced. Iodine (12 molecules) form a purple complex with starch in solution, but reduced iodine, iodide, (I-) is colorless in the presence of starch. CH,OH CH,OH о о снон Η от оснон + + 2H1 HOOH Vitamin C lodine Vitamin C Hydroiodic Acid (reduced) (oxidized) If we add iodine to react with the vitamin C in an acidie solution that also contains starch, then once we've oxidized all of the vitamin C, the l will remain, and a purple color will be produced. This color change is the basis for the titration reaction, and the purple color is used to determine the endpoint A word of caution: before you begin your titrations, it might be wise to plan your method of problem solving. What data do you NEED to meet the challenge? How are you going to approach the problem in order to solve it? Safety & Hazards: All solutions should be used in a well-ventilated area with eyewash and shower facilities. In addition to full coverage clothing and shoes, chemical splash goggles should be worn at all times. Gloves should be wom. Iodine STAINS. Collect iodine solution in a waste bottle. Equipment and Reagents: Equipment: You may use any equipment in the lab drawers or on the benchtops. If you need a specialized piece of equipment that is not in either place, request it from your instructor, but be prepared to justify why you need it. Reagents: vitamin C tablet, iodine solution, 0.2 M acetic acid, 2% starch solution, a lemon, a lime, an orange Part : Standardization of iodine solution Before you can begin testing the fruits for vitamin C content, it is necessary to standardize your iodine solution using a known quantity of vitamin C. What does "standardization" mean? Why do you need to do this? It is process of making something Conform to a standard. Take a vitamin C tablet and note the content in mg per tablet. You will want to dissolve the tablet in water. (What is the fastest way to dissolve something?) A suggestion: dissolve the tablet in a measured Smash it and mix it )

Answer 1

1)

Standardization is the process of determining the exact concentration of the analyte. During the standardization of the iodine solution, the unknown concentration of the iodine solution is determined by using a known concentration of the ascorbic acid. Thus, if a 1 M iodine solution, after standardization is determined to be 0.99 M, we can say that the 0.99 M iodine solution standardized.

2)

The fastest way to dissolve the tablet is to make it a powder and dissolve. The powdered form has more surface area than the tablet form. Thus, the powdered form has more area in contact with the solvent (water) and dissolves easily. Other methods are heating, stirring, etc.