unstable and inconvenient to work with‚ you will titrate vitamin C samples in this lab with potassium iodate‚ KIO3‚ in the presence of an acidic iodide solution. The iodate ion oxidizes iodide to iodine. IO3Ϫ ϩ 5IϪ ϩ 6Hϩ 1 3I2 ϩ 3H2O Notice that an equilibrium is established. To ensure that the reaction goes to completion‚ it is necessary to use excess iodide and to make the solution acidic. The iodine formed in this reaction immediately
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Title: Kinetics: The Rate of a Chemical Reaction Objectives: 1. To study the kinetics of chemical reaction‚ 2 I- + S2 O82- I2 + 2 SO42- . 2. To study the effects of reactant concentration (persulphate‚ S2O82-‚ and iodide‚ I-) and temperature on the rate of chemical reactions. ( i) Study the effect of 0.20M (S2O82-) on the rate of chemical reaction. ( ii) Study the effect of 0.10M (S2O82-) on the rate of chemical reaction. ( iii) Study the effect
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reaction has many alterations‚ the alteration used in this investigation is hydrogen peroxide and includes the use of‚ sodium thiosulfate‚ potassium iodide‚ and hydrogen peroxide. The use of starch solution is essential in this experiment as it acts as an indicator for the experiment turning the color of the solution dark blue in the appearance of iodine ions. This allows the end of the reaction to be determined. The clock reaction is shaped by two different reactions. The first reaction is the slow
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+ I2 Br2 + 2I- ( 2Br- + I2 • Down the group the outer electron is further from nucleus and more shielded so gained less easily 3) Trends in properties of the halides • The halides (chlorides‚ bromides and iodides) are reducing agents which lose an electron when they react • The ability to act as a reducing agent increases down the Group • Down the group the outer electron is further from nucleus and
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When a strong acid is present‚ hypochlorite ion changes to hypochlorous acid when the strong acid donates the H+ when it dissociates in the solution. In order to calculate the oxidizing capacity‚ the mass of NaOCl present in each trial should be determined using the volume of Na2S2O3 added in each
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oxidizing agent? What is the equivalent weight of H2O2 (Molar mass = 34.0 grams) in the above reaction? What is the normality of a 0.040 M H2O2 solution used in the above reaction? 8) Iodine reacts with thiosulphate ion (S2O3-2) in acidic solution to form iodide and tetrathionate ion (S4O6-2). Calculate the volume in mL of 0.100 M Na2S2O3 needed to react with 0.2538 g of I2. (Answer = 20.00 mL) 9) Thyroxine (C15H11I4NO4) is a hormone
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sulphate ions are present. The chemical equation for this reaction is: Fe2(SO4)3(aq) + BaCl2(aq) FeCl3(s) +
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oxidation of ascorbic acid by iodine solution. Iodine is relatively insoluble‚ but this can be improved by complexing the iodine with iodide to form triiodide as the following formula suggests: I_(2(aq))+〖I^-〗_((aq))↔〖I^-〗_(3(aq)) This triiodide ion can be used to oxidize vitamin C to form dehydroascorbic acid. In this reaction the triiodide ion is reduced to iodide ion‚ and ascorbic acid‚ C6H8O6 is oxidized to dehydroascorbic acid‚ C6H6O6. Aim The aim of this investigation is to discover the exact
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ANALYSIS OF VITAMIN C IN COMMERCIAL FRUIT JUICES BY IODOMETRIC TITRATION. SHAMSUL AZRIN BIN MD. KANAFE Final Year Project Report Submitted in Partial Fulfilment of the Requirement for the Degree of Bachelor of Science (Hons.) Chemistry in the Faculty of Applied Sciences‚ Universiti Teknologi MARA. APRIL 2009 This Final Year Project Report entitled “ANALYSIS OF VITAMIN C IN COMMERCIAL FRUIT JUICES BY IODOMETRIC TITRATION” was submitted by Shamsul Azrin Bin Md. Kanafe‚ in partial
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NaOH. Fe2+ + 2OH- Fe(OH)2 (dark green ppt) Reddish-Brown ppt. [k] Insoluble in excess aq. NaOH. Fe3+ + 3OH- Fe(OH)3 (red brown ppt) iron (II) iron(III) NOTE: The observations for both lead(II) and aluminium ions are similar. To distinguish them‚ add aqueous potassium iodide KI to both solutions.
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