• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Vitamin C. I will investigate whether orange juice contains the most Vitamin C and how I can speed up and slow down the oxidation process of Ascorbic Acid.

Extracts from this document...


Vitamin C in Fruit Juices Background: Ascorbic Acid, or more commonly known as Vitamin C, is a monosaccharide that has a five-membraned unsaturated ring with two hydroxyl groups attached to doubly bonded carbons. This feature means that Ascorbic Acid is readily oxidised to dehydroascorbic acid. This reaction is called oxidation because the Ascorbic Acid is loosing electrons. Ascorbic Acid deficiency leads to scurvy, a disease that shows weakness, small hemorrhages throughout the body that cause gums and skin to bleed, and loosening of the teeth. Vitamin C is a water soluble antioxidant, and plays a vital role in protecting the body. The body absorbs extra vitamin C in response to an infection. Because it is a water soluble vitamin, any unused vitamin C is excreted. The minimum daily requirement is 30 mg; the recommended daily allowance is 60-70 mg. C6H8O6 + C12H7NCl2O2 ----------> C6H6O6 + C12H9NCl2O2 The electrons lost from Ascorbic acid will be used to reduce one of my indicators Dichlorophenolindophenol(DCPIP), to DCPIPH and then to DCPIPH2. DCPIP (blue) + H+ ----------> DCPIPH (pink) DCPIPH (pink) ...read more.


Once I have diluted the DCPIP the risks are drastically reduced however I still need to wear goggles and a lab coat. Ascorbic Acid should be treated as an irritant and therefore I should wear goggles and a lab coat when handling it. I am using 5% Ethanoic acid however, it is not above 4 moles and therefore should be treated as an irritant just as DCPIP and Ascorbic Acid are. My solutions of Iodine will not be greater than 1M so they should be treated as an irritant not harmful and corrosive. I will always wear goggles and lab coats. When handling glassware I should be careful that none of it breaks, if it does I should ensure I do not touch the broken glass and seek help. Method Making up my Standard Solutions Ascorbic Acid- * Use the same scales throughout to ensure, if there is an error that it is the same error all the time. * Weigh out the mass of solid Ascorbic Acid (0.1g) by putting the solid in away from the balance so I do not spill any onto the balance, to make sure that I do not have less Ascorbic acid than I think I do. ...read more.


* Do a rough titration. * When doing your 5 real titrations, add starch to make determining the end point clearer. This is added near the end because if it is added at the start it can hold the ascorbic acid in a complex and the titration will not work properly. * Read off the titre at the bottom of the meniscus. * Repeat above procedures but for tropical juice and orange juice instead of Ascorbic Acid. The iodine solution, by reading the meniscus I can tell that this titre was 38.50 cm3 I found my Iodine titrations hard to do because they often formed big complexes with the Ascorbic Acid, preventing me to see the end point, so I will use DCPIP from now on. Investigating how to speed up and slow down oxidation After researching I found out that iron and copper ions can have an effect on the oxidizing ability of Ascorbic Acid. Copper Sulphate I added Copper Sulphate with Ascorbic Acid to see if that speeded up or slowed down its oxidation. Iron DCPIP http://www.chemistry-react.org/go/Faq/Faq_27690.html Ascorbic Acid http://wwwchem.csustan.edu/chem1112/1112vitc.htm DCPIP http://upload.wikimedia.org/wikipedia/commons/a/aa/DCPIP-reduction- 2D-skeletal.png DCPIP http://en.wikipedia.org/wiki/Dichlorophenolindophenol Hazcards http://moodle.colchsfc.ac.uk/mod/resource/view.php?inpopup=true&id=20361 ?? ?? ?? ?? Sam Hennessy The Sixth Form College, Colchester. Chemistry ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Organic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Organic Chemistry essays

  1. Peer reviewed

    Analysis Of Commercial Vitamin C Tablets

    3 star(s)

    0.682g of potassium iodate solid was weighed out. It was then made up to 250cm3 using a volumetric flask. 2. Sodium thiosulphate solution was added to 25cm3 of the iodate solution until the solution turns to pale yellow. Iodide and sulphuric acid was added beforehand. Starch solution was added, and more sodium thiosulphate solution was added until it reaches the end point.

  2. Free essay

    Experiment to determine the order of the reaction of Iodine with Acetone by using ...

    In consecutive reactions the rate-determining step often determines the kinetics. In consecutive first order reactions, a steady state approximation can simplify the rate law. The activation energy for a reaction is experimentally determined through the Arrhenius equation and the Eyring equation.

  1. The aim of this experiment is to produce Aspirin. This is an estrification in ...

    = 0.0166 moles The reaction is 1:2 ratio. One mole of aspirin needs two moles of NaOH. Therefore the number of moles of aspirin used: 0.0166 = 0.0083 moles 2 The mass of aspirin that reacted with NaOH M = n x Mr = 0.0083 x 180 = 1.4850g Therefore the mass of aspirin that didn't react with NaOH.

  2. Chem Lab report. Objective: To determine the content of vitamin C in ...

    acid accurately. It is because the amount of potassium iodide added was obviously in an excess and sulphuric(VI) acid was just used to provide an acidic medium for the reaction to take place. These two chemicals were not involved in the calculation and the amount of them did not affect the calculation.

  1. investigating the amount of ascorbic acid present in fruit

    NBS solution can cause irritation to the eyes and skin if split and also more harmful effects such as burning pain in the nose and throat, coughing & shortness of breath. The procedures I took to protect myself from this happening were to: * Wear safety goggles in case some of this harmful solution came into contact with my eyes.

  2. Determination of the formula of Hydrated Iron (II) Sulphate crystals

    percentage error for method one, the percentage error must be found for all four of these and added together. To calculate the percentage measurement error, you use number that is half the smallest calibration/measurement that the measuring device can measure for example, for the top pan balance, it can measure

  1. hydrated copper sulphate

    In comparison to 23.1(1st titre) and 24.5 (3rd titre) this value was relatively large, therefore would affect the average, so it was not included. This was to ensure as accurate results as possible. As a whole my experiment was accurate because the formula I produced was correct.

  2. Vitamin C. The objective of this project is the determination of the amount of ...

    the comparison of the content of vitamin C of the same type of fruit juice of Vita brand and Hi-C brand; 3. the Best buy fruit drink which contains relatively large amount of vitamin C with the lowest price. Experiment Objective To determine the amount of the ascorbic acid (vitamin C)

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work