Iodide Formula – Structure, Properties, Uses

Iodide Formula: Iodine, denoted by the symbol I and occupy an atomic number of 53, stands as the heaviest among the stable halogens. It is categorized as the fourth halogen and is a constituent of group 17 within the periodic table. Naturally, iodine is found in trace amounts in certain foods, playing a crucial role in the body’s production of thyroid hormones that regulate metabolism. 

It is primarily sourced from animal protein-based foods and sea vegetables, with additional contributions coming from fortified items such as bread, cereals, and milk. Iodine compounds, or iodide salts, are employed in various applications, including pharmaceuticals, disinfectants, printing inks, dyes, animal catalysts, feed supplements, and photographic chemicals.

Regarding iodide, it represents an ion, I-, bonded with iodine. Iodide salts are recognized as mild reducing agents and have the capability to react with oxygen to produce iodine. In everyday usage, iodide is commonly integrated into iodized salt and ranks as one of the largest monatomic anions.

Iodide Formula

Iodide is a chemical formula written as I–. Iodine, the element it comes from, has seven outer electrons, which makes it want to react with other elements to fill up its outer shell. However, among similar elements, iodine is not very good at this. On the other hand, the iodide ion (I–) is quite good at making other substances react with it to give back iodine. So, even though iodine doesn’t easily react with other elements, iodide can help make reactions happen.

Iodide Formula and Valency

Iodide Formula: The chemical formula for iodide is “I–”. It represents an iodine atom that has gained an extra electron, resulting in a negative charge (anion).

Valency of Iodide: The valency of iodide is -1. This means that iodide ions have an effective charge of -1 and can form ionic bonds by accepting one electron to achieve a stable, full outer electron shell. In this process, iodide ions are attracted to elements with a valency of +1, like sodium (Na), to form compounds such as sodium iodide (NaI), where the overall charge is neutral due to the combination of the +1 sodium cation and the -1 iodide anion.

Iodide Formula and Charge

The chemical formula for iodide is “I–.” This represents an iodine atom that has gained an extra electron, resulting in a negative charge (anion). Therefore, the charge of the iodide ion is -1. The negative charge is indicated by the minus sign (–) in the formula, denoting that the iodide ion carries one additional electron compared to a neutral iodine atom. This extra electron gives the iodide ion an overall negative charge of -1. Iodide ions can form ionic bonds with elements that have a positive charge to create electrically neutral compounds.

Iodide Formula Structure

To understand the structure of iodide ions, we begin by examining the structure of iodine. Iodine is a chemical element denoted by the symbol I. It is situated in the 17th group of the periodic table and possesses seven valence electrons. Normally, iodine is electrically neutral, which means it has no charge.

However, when iodine transforms into an iodide, it gains a negative charge. This means it gains an extra electron, bringing its total valence electrons to eight, which makes it highly stable. The negative charge is a result of iodine gaining this electron, and so we call it the iodide ion.

Physical Properties of Iodide

• Molecular Weight: Iodide has a molecular weight of 126.904 grams per mole.
• Density: It has a density of 3.13 grams per cubic centimeter (g/cm³).
• Boiling Point: Iodide’s boiling point is 184.3 degrees Celsius (°C).
• Melting Point: Its melting point is 113.7°C.

Chemical Properties of Iodide

Chemical Formula: The chemical formula for iodide is I–.

Solubility: Iodide is soluble in water, meaning it can easily dissolve in water.

Reaction with Sodium Salt: Iodide compounds, when combined with sodium salt, react to produce sodium nitrate and lead iodide according to the equation:

Pb(NO₃)² + 2 NaI → 2 NaNO₃ + PbI₂

Reaction with Potassium Iodide Salt: Potassium iodide salt, when mixed with chlorine, results in the formation of iodine and potassium chloride as shown in the equation:

2 KI + Cl₂ → 2KCl + I₂

Harmful Effects of Iodide

Thyroid Issues: Consuming too much iodide can interfere with the production and release of thyroid hormones, leading to conditions like goiter (an enlarged thyroid gland) and hypothyroidism (underactive thyroid).

Oral Discomfort: Excessive iodide intake may cause a burning sensation in the mouth.

Heartbeat Irregularity: It can result in an irregular heartbeat.

Dental and Gum Discomfort: Iodide excess may lead to soreness in the teeth and gums.

Digestive Upset: It might cause stomach discomfort.

Safety Measures for Handling Iodide

Avoid Contact: Prevent direct contact with your skin and eyes.

Wear Eye Protection: Use protective safety glasses when handling iodide.

Avoid Inhalation: Refrain from breathing in iodide vapors.

Ingestion Warning: Iodide can be harmful if swallowed.

Eye Care: If iodide comes into contact with your eyes, flush them with water. Seek medical attention if irritation persists.

Uses of Iodide

Printing and Dyes: Iodide salts find application in printing inks and dyes.

Animal Feed Supplement: They are used as supplements in animal feed.

Radiation Protection: Compounds like potassium iodide safeguard the thyroid gland from potential radiation damage caused by radioactive iodine.

Skin Disinfection: Iodide is utilized to disinfect the skin before surgical procedures. It possesses disinfectant properties and is less affected by factors like water pH or organic content compared to chlorine. However, its disinfection effectiveness decreases in cold water.