# Preparation and Standardization of 0.05 M Iodine Solution

Aim: To Prepare and standardize 0.05 M Iodine Solution by using As2O3

Name: 0.05 M Iodine solution

Ingredients Required for Preparation and Standardization of 0.05 M Iodine Solution:

• Iodine
• Potassium Iodide
• Arsenic Trioxide
• Hydrochloric Acid
• Sodium Hydroxide
• Methyl Orange
• Sodium Bicarbonate
• Starch Solution

## How to Preparation and Standardization of 0.05 M Iodine Solution

To Prepare this solution, you’ll need to follow these steps:

• First, take about 14 grams of iodine.
• Then, dissolve it in a solution containing 36 grams of potassium iodide in 100 milliliters of distilled water.
• Add 03 drops of hydrochloric acid.
• Dilute the solution with more distilled water until you have a total of 1000 milliliters.

## How to Standardization of 0.05 M Iodine Solution

To check the strength of the solution, follow these steps:

• Accurately weighs about 0.15 grams of arsenic trioxide, which has been dried at 105 degrees for an hour.
• Dissolve it in 20 milliliters of 1M sodium hydroxide by warming it if needed.
• Dilute this with 40 milliliters of distilled water.
• Add 0.1 milliliter of methyl orange solution and slowly add dilute hydrochloric acid until the yellow color changes to pink.
• Next, add 2 grams of sodium bicarbonate, dilute with 50 milliliters of distilled water, and add 3 milliliters of starch solution.
• Titrate this with 0.05 M iodine until a permanent blue color is produced.
• Keep in mind, that each milliliter of 0.05 M iodine is equivalent to 0.004946 grams of As2O3.

### How to Calculate 0.05 M Iodine Solution

To calculate the strength, use this formula:

Reference: Indian Pharmacopoeia