• 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 ...

    Acid reactions, the formation of salts, and ion exchange are fast reactions. When covalent bond formation takes place between the molecules and when large molecules are formed, the reactions tend to be very slow. Physical State The physical state (solid, liquid, or gas)

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

    Method 2: Measurement uncertainties Percentage uncertainty from weighing the iron sulphate (0.005/2.92) x 100 =0.17% Percentage uncertainty from measuring the burette (0.05/21.65) x 100 =0.23% Percentage uncertainty from measuring 25.00cm� in the volumetric flask (0.15/25.00) x 100 =0.60% Percentage uncertainty for measuring 25cm� using the pipette (0.05/25)

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

    * Approximately 1.5g of aspirin was accurately weighed out in a conical flask using an analytical balance. * 25 cm3 of 1.0 mol dm-3 sodium hydroxide solution was added to the conical flask and aspirin. * 25 cm3 of distilled water was also added to the conical flask.

  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. Comprehensive and Detailed Chemistry notes

    electrical circuits and blowing agents for packaging -- Gases from CFGC products were released into the atmosphere -- Halons are haloalkanes in which all the hydrogen atoms have been replaced by bromine, fluorine and/or chlorine atoms -- Halons were developed for use in extinguishing fires, particularly in large computer systems and aeroplanes.

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

    Also, it should only be poured out enough amount of vitamin C from the volumetric flask just about to use and then stopper it immediately. Third, sodium thiosulphate solution is unstable and it will be easily oxidized by air. Thus the actual concentration of it will be lower and so lead to an error to the experiment.

  2. 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.

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