How is WIJS solution prepared?
Table of Contents
Iodine Content: Pour 150 mL of saturated chlorine water into a 500 mL Erlenmeyer flask and add some glass beads. Add 5.0 mL of Wijs reagent by pipet, shake and heat to boiling. Boil briskly for 10 mins., cool and add 30 mL of 2% sulfuric acid solution and 10 mL of 30% potassium iodide solution.
What is WIJS solution?
Definition of Wijs method : a method for determining the iodine number (as of an oil or fat) that consists in adding a solution of iodine monochloride in glacial acetic acid and estimating the excess of unused halogen by titration with sodium thiosulfate.
How do you make Hanus solution?
Hanus solution ( it’s prepared by dissolving 18.2 g of iodine in 1L of glacial acetic acid and then add 3 ml of bromine water for increasing the halogen content. 0.1 N Sodium thiosulfate solution.
What chemical is Wijs method?
This procedure, originally used for the analysis of oils and fats, is currently known as Wijs’ method. It is based on the reagent ICl, iodine monochloride, dissolved in glacial acetic acid (0.1 mol L−1 solution).
What is the function of 1% starch solution in the Wijs method?
Starch solution is commonly used as an indicator for detecting the presence of iodine.
Which indicator is used in Wijs method for determination of iodine value?
Wijs/ Hanuš method Wijs introduced modifications in Hübl method by using iodine monochloride (ICl) in glacial acetic acid, which became known as Wijs’s solution, dropping the HgCl2 reagent. Alternatively, J. Hanuš used iodine monobromide (IBr), which is more stable than ICl when protected from light.
What is the role of WIJI’s solution?
Intended Use: Wij’s solution is analytical reagent used to determine the iodine value of a substance. Fatty acids present in sample reacts with excess of Wij’s solution.
What is iodine number of fat?
The iodine value (IV) indicates the degree of unsaturation of a fat or oil. It is defined as the number of grams of iodine absorbed by 100 g of fat.
What is Hanus solution?
[′han·əs sə‚lü·shən] (analytical chemistry) Iodine monobromide in glacial acetic acid; used to determine iodine values in oils containing unsaturated organic compounds.
What is acid value of fat?
The acid value is defined as the number of milligrams of Potassium hydroxide required to neutralize the free fatty acids present in one gram of fat. It is a relative measure of rancidity as free fatty acids are normally formed during decomposition of triglycerides.
What is saponification value and iodine?
Saponification value (SV), iodine value (IV), acidity (AN), and peroxide value (PV) are the most commonly used parameters in characterizing the quality of oils and fats. These parameters are widely used to determine purity (SV), number of unsaturated compounds (IV) and free fatty-acid content (acidity).