Experience 6. Definition the quality of diethyl cther During storing diethyl ether under the influence of sunlight in the presence of oxygen of it oxidizes and forms peroxide compounds, which often cause explosions during careless work.

bernat в категроии Химия, вопрос открыт 23.03.2018 в 03:14

Peroxides are detected by reaction with potassium iodide. To remove the peroxides, the ether is shaken with a concentrated ferric sulfate solution until the reaction with potassium iodide disappears. Reagents: 1. diethyl ether 2. 10% solution of potassium iodide 3. 10% solution of hydrochloric acid 4. 0.5% starch solution Working process In a test tube add 4-5 drops of diethyl ether, add 2-3 drops of a 10% solution iodide and 2 drops of a 10% solution of hydrochlorie acid. hen potassium iodide is present in ether, potassium iodide is oxidized with liberation of free iodine, which dissolves better in ether than in water and therefore stains the ether layer yellow. If the color is weak, 2 drops of 0.5% starch solution are added to the mixture. There is a blue coloration of the complex of iodine with starch? can somebody solve it ? with the reasons ! thanks