What is WIJS solution?
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.
Is iodine solution a hazard?
Higher exposures may cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency, with severe shortness of breath. ► Iodine can cause headache, metallic taste, nausea, vomiting, diarrhea and abdominal pain.
How do you make a WIJS solution?
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 are precautions that must taken in an iodine solution?
Handling: Use with adequate ventilation and do not breathe dust or vapor. Avoid contact with skin, eyes, or clothing. Wash hands thoroughly after handling. Storage: Store in General Storage Area [Green Storage] with other items with no specific storage hazards.
What is the toxicity of iodine?
Iodine toxicity may lead to thyroiditis, hypothyroidism, hyperthyroidism, and thyroid papillary cancer. Clinical features of iodine toxicity from oral ingestion can range from mild to severe. Mild symptoms consist of GI upset, nausea, vomiting, and diarrhea, which may progress to delirium, stupor, and shock.
What is starch indicator used for?
Starch solutions are used as indicators in the detection of the endpoint of titrations involving Iodine solutions.
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 function of 1 starch solution in the Wijs method?
Starch solutions are often used as indicators for detecting the presence of iodine. Generally, a 1% starch solution will produce a nice, deep-blue color in the presence of iodine. The more concentrated the starch solution, the deeper blue in color is the resulting solution.
How can radioactive iodine be harmful to humans?
Iodine is needed by your thyroid gland to produce thyroid hormones. However, exposure to unnecessarily high levels of nonradioactive and radioactive iodine can damage the thyroid. Damage to the thyroid gland can result in effects in other parts of your body, such as your skin, lung, and reproductive organs.
What is starch solution indicator?
Starch solution is commonly used as an indicator for detecting the presence of iodine. When starch and iodine are present together, they form a deep-blue starch–iodine complex. The deep-blue color of the complex is due to the pentaiodide anion, I5 –.
What is the pH of starch indicator?
5 to 7
Specifications
| Appearance | Translucent liquid |
|---|---|
| Percent Purity | 0.50% |
| Odor | Slight potato-like odor |
| Packaging | Poly natural |
| pH Range | 5 to 7 (2% solution) |
What is the significance of iodine value?
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 are some disadvantages of using starch as an indicator?
It will be agreed that the chief disadvantages attending the use of starch are : (1) the insolubility of starch in cold water ; (ii) the instability of starch dispersions in water, in consequence of which a stock solution soon deposits a flocculent precipitate of retrograded starch ; (iii) that starch gives with iodine …
What is the purpose of adding starch to the titration mixture?
In an iodometric titration, a starch solution is used as an indicator since it can absorb the I 2 that is released. This absorption will cause the solution to change its colour from deep blue to light yellow when titrated with standardised thiosulfate solution. This indicates the end point of the titration.