Analysis of Commercial Vitamin C Tablets

The number of moles of ascorbic acid neutralized in the experiment is given by multiplying the moles of NaOH used (0.00235128 mol) by the unit conversion coefficient (1 mol ascorbic acid/1 mol NaOH).

1. To titrate a hydrochloric acid solution of “unknown” concentration with standardized 0.5M sodium hydroxide.

Add 3 drops of iodine solution * Shake it well,

Enter the precise mass in GRAMS of the potassium iodate used to prepare your primary standard solution.

In this experiment redox-based titrimetric analysis was used to determine the amount of ascorbic acid (Vitamin C) contained in a serving of lemonade. This was done to confirm the 100 percent recommended daily allowance claimed on the package for a serving of Country Time Lemonade. The titration method used was adding a thyodene indicator to the analyte (lemonade solution) there is a visible colour change when the endpoint of the reaction between the titrant (KIO3) and the analyte occurs. The following reactions show how this titration method is viable. (Draw in reactions) KIO3 first reduced with iodide (I-) to generate iodine (I2 ) which then oxidized the ascorbic acid within the lemonade. Once all the ascorbic acid had reacted any iodine

ii. The second part of the titration series involves titration of NaOH with Hydrochloric acid (HCL). Again, three reps of titration and a blank titration have to be completed. A volumetric pipet is used to measure 10.00mL of HCL into three labeled conical flasks. Then the flasks are filled with deionized water until about the 50mL mark. A buret is

Before the synthesis of the Copper Iodine Compound, the identities provided (CuNO3)2 and Nal weighed 1.65 g and 4.7 g, respectively. After being weighed, the (CuNO3)2 exhibited a blue color, while the Nal, through observation, was a white color. However, when both identities were combined, the product turned into a brown and red rocky material. Once 20 mL of deionized water was added, the product quickly turned pale pink paste. After the solution was repeatedly washed with a total of an additional 100 mL of deionized water, the product was powdery and pink with small grains, and was left to air-dry. Once the product was air dried, it was observed to be a pale pink color, while the filter paper was stiff as the product was hard and dry. Therefore, the solid was scraped off onto a recrystallizing dish. However, the mass of an empty recrystallizing dish needed to be recorded in order to compare how much of the synthesized copper iodide was obtained. Within this case, the empty recrystallizing dish used weighed 32.01 g, the product on the empty dish weighed 1.03 g, having a total weight of 33.04 g.

These equations can only be carried out and be visible after the iodine has completely reacted with thiosulphate added – two moles of thiosulphate for every mole of iodine. Once all the thiosulphate has been used up in the reaction, the colour will start to appear.

During a titration the pH of the solution will be monitored using a pH meter from that we get a titration curve. The titration curve is then used to determine the equivalent molecular weight and Ka value of the unknown weak acid, from that we are

Today there are many uses. Iodine salts are often used in pharmaceuticals and disinfectants, printing inks and dyes, catalysts, animal feed supplements, photographic chemicals, and sometimes polarizing filters for LCD displays. It is often added to small amounts of table salt in order to avoid iron deficiency affecting the thyroid gland.

The riboflavin standard solution (0.100ppm) was prepared by diluting 25 µL with the solvent that was previously made. A B-Super Complex vitamin tablet was then weighed. Afterward, the tablet was crushed with a mortar & pestle and weighed again. All of the solid was transferred into a 100ml beaker and 50ml of the solvent was added. After stirring for 15min the solution was transferred to a 100ml flask and was diluted to the mark with the solvent.

Iodine is a stain, be careful not to get it on your clothes and rinse

Add the same amount of Benedict’s solution in each tube and for the ones that need iodine use the same amount.

Vitamin C is an organic compound that is also known as ascorbic acid. The molecular formula for Vitamin C is C6O8H6. This structure contains a 5-membered ring. Vitamin C contains 4 alcohol functional groups, an alkene, and an ester. Within the ring it contains one double bond, the carbon=carbon bond in the ring structure, this is an alkene functional group. The Vitamin C structure also contains an ester which helps form the five-membered ring.

When the sulfuric acid was added to copper (II) oxide, the solution turned blue. This was due to the formation of aqueous copper (II) sulfate, which produced the copper ions to change the color of the solution.