Oxidation iodide ion

Sfi.f-Test K.4B In aqueous solution, cerium(lV) ions oxidize iodide ions to solid diatomic iodine and are themselves reduced to cerium(III) ions. Write the net ionic equation for the reaction. 

Substances containing active chlorine or bromine oxidize iodide ions — if necessary under the influence of UV light - to iodine, which reacts with starch to yield the well-known intense blue starch-iodine inclusion complex. 

At the end of this period the solution was removed from the condenser while still hot and titrated immediately with 0.002500 N sodium thiosulfate before any appreciable oxygen could be absorbed and oxidize iodide ion to triiodide ion. The disappearance of the yellow color of triiodide ion against a white background was used for the end point. These solutions usually had a slight brown tint at the end point, which was assumed to be organic matter distilled over from the soil. Accordingly, the blank was usually titrated first and its final color was used as a standard end point color for the other three solutions run with it. 

The products of perfluorination are both white, very different from the original black hydrocarbon polymers. Both materials are moisture-sensitive powders and slowly degraded by atmospheric moisture, 6 more quickly than 5. The materials oxidize iodide ion to iodine owing to the presence of the N—F moiety. A series of iodometric titrations showed that 6 required twice the number of equivalents of titrant as did 5. This result supports the proposed structures 6 having twice as many N—F moieties as 5. 

Neither Cr(VI) nor Fe(III) can oxidize iodide ions rapidly. However a mixture of Cr(VI) and Fe(II) forms iodine rapidly from iodide ions. The oxidation of I is said to be induced by the Fe(II) — Cr(VI) reaction. At high [I ]/[Fe ] ratios, the induction factor (ratio of H oxidized per Fe + oxidized) is 2.0. Interpret this behavior, detailing the intermediates involved. 

HNO2 + H2S S + 2NO + 2H2O HNO2 + 3H2S 3S + NH3 + 2H2O In acid medium it oxidizes iodide ion to iodine ... 

From the E° of half-reaction 15.22, it would seem that the nitrate ion present from the dissolution of the brass should also oxidize iodide ion. This E° value, however, refers to standard conditions, which implies 1 mol L 1 H+, whereas we have adjusted the pH to near neutrality. Suppose the pH is adjusted to 7.0, that is, [H+] = 1 x 10 7 mol L 1, while [N02-] and [N03-] retain their standard-state values of unity the corresponding EMF for the half-reaction 15.22 is then... 

Ozone is an extremely powerful oxidizing agent. In fact, of the common oxidizing agents, only F2 is more potent. A standard method for detecting ozone in polluted air is to pass the air through a basic solution of potassium iodide that contains a starch indicator. The ozone oxidizes iodide ion to iodine, I2, which combines with the starch to give the deep blue starch-iodine complex ... 

Fluorine is more electronegative than the other elements, and it ac cordingly is able to take electrons away from the anions of these ele inents. Similarly chlorine is able to oxidize both bromide ion and iodide ion, and bromine is able to oxidize iodide ion ... 

A halogen higher in the periodic table is a stronger oxidizing agent than one lower down. Thus, chlorine can oxidize bromide ions or iodide ions from solution, and bromine can oxidize iodide ions. Here, chlorine displaces bromine ... 

Thus iron(III) should oxidize iodide ion to iodine. This makes the iodide ion/iodine half-reaction the anode. The standard emf can be found using Equation (19.1). 

Peroxy acids are useful oxidizing agents and are generally analysed on the basis of their ability to oxidize iodide ion to iodine which can be determined titrimetrically or colorimetrically. They also oxidize alkenes to epoxides, ketones to esters or lactones, thioethers to sulphoxides and sulphones, and tertiary amines to amine oxides. 

Upon the addition of sodium hydroxide solution, oxygen dissolved in water combines with manganese II ions to form higher-grade manganese oxides, which are dissolved on acidification as manganese III ions and oxidize iodide ions to iodine. The iodine thus formed is titrated with sodium thiosulphate. The consumption of sodium thiosulphate solution used for adjustment is a measure of the oxygen content in the water. 

One of the most obvious techniques is based upon iodimetry because it has been used as a standard or reference method in spite of its drawbacks. Ozone oxidizes iodide ion in solution ... 

Hydroperoxides in ethers can be detected by shaking a small amount of the ether with an acidified 10% aqueous solution of potassium iodide, KI, or by using starch iodine paper with a drop of acetic acid. Peroxides oxidize iodide ion to iodine, I2, which gives a yellow color to the solution. Hydroperoxides can be removed by treating them with a reducing agent. One effective procedure is to shake the hydroperoxide-contaminated ether with a solution of iron(ll) sulfate in dilute aqueous sulfuric acid. You should never use ethers past their expiration date, and you should properly dispose of them before then. 

The hypochlorous acid (HOCl) that is formed decomposes slowly to give oxygen. Bromine does not react with water under acid conditions. In the case of iodine, the partial pressure of oxygen in the air is sufficient to oxidize iodide ion back to the elemental form [analogous to Eq. (13) in reverse]. 

Chlorine dioxide oxidizes iodide ion in aqueous solution to iodine chlorine dioxide is reduced to chlorite ion. 

Concentrated sulfuric acid oxidizes iodide ion to iodine, I2. Write the balanced equation for this reaction. 

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