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

Analysis of sulphur dioxide content in wine.doc

Extracts from this document...


Analysis of sulphur dioxide content in wine Objective To determine the amount of sulphur dioxide, an antioxidant, present in wine by using volumetric analysis. Principle All free SO2 molecules is first convert into SO32- by NaOH solution: SO2 + 2OH- � SO32- + H2O Acidification of the solution liberates all SO2: 2SO32- + 2H+ � 2SO2 + 4H2O which is then titrated with 0.0057M iodine solution in which starch is used as end-point indicator: SO2 + I2 + 2H2O � 2HI + H2SO4 Chemicals white wine (carbonated), 1M NaOH, 2M H2SO4, 0.0057M I2, starch solution Apparatus volumetric apparatus, pipette, measuring cylinder, dropper, white tile Procedure 1.> Find out the volume of wine from the label on the bottle. 2.> Pipette 25cm3 of white wine into a conical flask. 3.> Add about 12cm3 of 1M NaOH and stand for about 15 minutes. 4.> Add about 10cm3 of 2M H2SO4 to the mixture and then few drops of starch solution as indicator. ...read more.


Even small amount of air, over a period of time, can adversely affect the wine. ~The need for wine additives~ Other than anti-oxidation, additives are added to wine to enhance its flavour and colour. The example are sugar, to reduce bitter taste of wine; ester, as flavouring agent to enhance flavour; sulphur dioxide, as antioxidant. Some wine which is needed to store for a long time especially need to preserve. Since dilute ethanol in wine can prevent bacterial growth, anti- oxidation is thus more important in preservation of wine. ~Safety of using wine additives~ No additives may be used unless it has been extensively tested on animals. Considerable research has been carried out in order to observe whether the additives affect growth, reproduction, or prevalence of cancer. These data are then used by experts to assess the risks to humans in using the additives. ~Sulphur dioxide as antioxidant~ Sulphur dioxide, including its salts, namely, sulphites (SO32-) and bisulphites (HSO3-) can preferentially react with atmospheric oxygen into harmless SO42-, thus prevent oxidation of wine. ...read more.


~Result~ By the experiment, SO2 content in wine is 44.88 mgdm-3 which is much lower than the limit of 450 mgdm-3 stated. However, this value is supposed to be not accurate since in this experiment, carbonated wine is used, and the carbon dioxide evolves will affect the measurement by pipette and can draw away the free sulphur dioxide in wine. So, non-carbonated white wine should be use (since colour may affect the detection of end-point). Although a bottle of wine doesn't exceed the limit of 450 mgdm-3, the heavy drinking of alcohol can damage heart, kidney, liver and central nervous system. Other than as antioxidant in wine, SO2 is also widely used in bleaching industry, Contact Process in manufacturing sulphuric acid and disinfectant. Conclusion Sulphur dioxide is used in wine as antioxidant. However, due to its toxicity and allergy to asthma patient, the limit of using sulphur dioxide must be set. ?? ?? ?? ?? ...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 Inorganic Chemistry section.

Found what you're looking for?

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

Here's what a star student thought of this essay

4 star(s)

Response to the question

This piece covers all necessary aspects such as experimental data, discussion and conclusion to varying degrees of depth and better consistency would improve its grade. Overall the candidate sets out their calculations concisely but perhaps more detailed explanation of the ...

Read full review

Response to the question

This piece covers all necessary aspects such as experimental data, discussion and conclusion to varying degrees of depth and better consistency would improve its grade. Overall the candidate sets out their calculations concisely but perhaps more detailed explanation of the steps of the calculation would make their work easier to understand, it is important that coursework is clear at all times so that examiners know where to award marks. The conclusion needs to answer the question and recap the main points in detail which is not done here.

Level of analysis

In order to achieve top grades the candidate would need to match the detail found in their discussion, which incorporates evidence of additional reading and thorough discussion of the use of sulphites in wine and the reason for doing so. The areas labelled precautions and possible error would need to be expanded and more detailed analysis provided for both. It would be wise to include health and safety notes at this level of study and more specific details about the experimental procedure and possible variables would ensure the experiment was as reliable as possible. Always imagine you are explaining the procedure to someone who has never carried it out before and ask yourself what they would need to know to repeat it as exactly as possible. The conclusion is not that of an A level student and should include evaluation of the analysis and link this to the real life implications mentioned in the discussion e.g. health problems.

Quality of writing

Some errors are present in terms of grammatical constructions which make the coursework difficult to understand and as a consequence prevent its fluency. Proofreading any work to ensure it makes sense is vital to achieve maximum communication marks.

Did you find this review helpful? Join our team of reviewers and help other students learn

Reviewed by tomcat1993 01/04/2012

Read less
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 Inorganic Chemistry essays

  1. Peer reviewed

    Determining the concentration of acid in a given solution

    5 star(s)

    sodium carbonate in my solution to make the solution 0.1 mol dm-3. Indicators 5 6 The concentrations I will be using of sodium carbonate and sulfuric acid are weak. Sulfuric acid is a strong acid, yet sodium carbonate is a weak alkali.

  2. Bleaching experiment. Estimation of available chlorine in commercial bleaching solution.

    Steps (9) - (17) were repeated for few times. *For transferring or carrying different solutions, it was reminded that to repeat the step 1 to step 3.For burette or pipette, it was rinsed with the solutions which would be transferred. Besides, the conical flask should be swirled throughout the titration.


    * It can also harm intestines if drunk. Ethonoic Acid: Ethanoic acid has very strong and sharp odour and smell. Procedure: Titration of hydrochloric acid with standard sodium hydroxide solution 1. Using a pipette and filler, transferred 50.0 cm of NaOH solution into the polystyrene cup. Allowed to stand for a view minutes.

  2. Preparation and analysis of a complex metal salt

    2nd titration 3rd titration Final burette reading (cm3) 20.3 37.8 34.0 Initial burette reading (cm3) 2.3 20.3 16.7 Volume of EDTA used (cm3) 18.0 17.5 17.3 Average volume of EDTA used: (17.5 + 17.3)/2 = 17.4 cm3 * No. of moles of EDTA added: 17.4 /1000 x 0.01 = 1.74

  1. determination of the percentage of oxalate in iron (II) oxalate by redox titration

    24H+ +5FeC2O4 � 3Mn2+ + 10CO2 + 5Fe3+ + 12H2O As 17.3 cm3 of MnO4- is used, no. of mole of MnO4- = 0.02007 x (17.3 � 1000) = 0.000347211 mol. Mole ratio of MnO4- to FeC2O4 = 3:5 No. of mole of FeC2O4 (10 cm3) = 0.000578685 mol. No.

  2. The preparation, analysis, and reactions of an ethanedioate complex of iron

    When the solution was heated to 70?, the thermometer was removed and washed down, and was titrated with the standard, approximately 0.02M solution of permanganate. A pink color was persisting for 30 seconds at the end-point. The resulting solution was kept for the determination of iron in (b).

  1. Essay on the Oxides of Period 3 Elements

    Silicon dioxide also known as silica is similar to the aluminium oxide. It does not react with water due to the inability to dissolve in water. Silicon dioxide is made up of a giant structure due to extensive network of covalent bonds in the crystalline lattice structure that extends to infinity.

  2. The aim of this investigation is to analyse what cations and anions are present ...

    I came to this decision by doing a flame test which showed sodium as the colour orange. I tested the Mummion crystals with the flame test and it gave me the colour orange and by testing all the chemicals I had I came to a decision that sodium was the cations in the Mummion crystals.

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