Question

2) What chemical reaction does the titrant contribute to this experiment?

CHEM 1A Experiment #8: Measuring the Vitamin C Content of Emergen-C™ Objectives: Students will learn how to use a burette. Students will learn how to use the iodine starch indicator system to monitor oxidation/reduction reactions. • Students will learn how to conduct a titration to determine the amount of analyte in an unknown solution. • Students will learn about ascorbic acid's role as a biological reducing agent. Introduction: Vitamin C, also known as ascorbic acid, is a molecule that serves as a biological reducing agent. It is found in many fruits and vegetables, including citrus fruits, tomatoes, strawberries, broccoli, kale, and Brussels sprouts, to name just a few. The oxidation of ascorbic acid liberates two electrons that can be delivered to a variety of substances, including biomolecules, metal ions, and iodine molecules, as is the case with this experiment. ON HOM HO 200 0-100 + 2 + 2H C C 0 0 Dehydroascorbic Acid Ascorbic Acid Ascorbic acid (C.H.O.) plays a key role in human health by aiding in the production of a type of connective tissue called collagen. More specifically, ascorbic acid facilitates the activity of several key enzymes that are required for collagen synthesis. Scurvy is a disease caused by insufficient collagen synthesis attributed to vitamin C deficiency. The disease is characterized by deterioration of the skin, joint pain, bleeding in the joints, and anemia. In advanced cases, the patient may develop swollen gums and experience tooth loss, as well as organ failure, convulsions, coma, and death. In addition to preventing scurvy, vitamin C also plays a role in the absorption of iron and in the deactivation of a class of potentially destructive molecules called free radicals. The role vitamin C plays in human health is multifaceted and indisputable, so it will come as no surprise that it is commonly added to beverages marketed as 'healthy alternatives to sugary carbonated drinks. Whether or not beverages like Emergen-C™ are actually, the fact remains that ascorbic acid is an essential nutrient. It is required for the normal functioning of the human body but it cannot be produced by the multitude of biochemical pathways that comprise human physiology. In this experiment, you will use an oxidation-reduction reaction to determine the amount of vitamin C in a packet of Emergen-C Super Orange (9.1 g of drink powder contains 1000 mg of ascorbic acid). The procedure you will follow, called a redox titration, involves slowly adding an oxidizing agent into a solution containing ascorbic acid. Once the oxidizing agent (the titrant) has consumed all of the ascorbic acid, a side reaction will occur that produces a color change in the solution. The moment that this color change occurs, the redox titration has reached its end point and the volume and

Answer 1

Here in this experiment Kiz is. bitrant. This titrar titrates the sairple which contain ascorbic acid (C6H806), godide (In) in presence of acid (4). Here zor (coming from full disso- ciation of & 203) oxidises ar to uz in presence of and as 20z& si +64 - 372 +3th 0. Now, de produced in above reaction. dopidly oxidizer the as cossic acid to dehydro ascorbic acidai HO Hoc +21 20 + 12 + 2H+ Ascorbic oeid De hydro ascorbic oid. Here k on oxidise - to Izashich again oxidises asorbie aid of itself converted to I-