The aqueous solution of hydrogen iodide is dubbed hydroiodic acid, and also it is the most acidic amongst the hydrohalides.

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Formula and structure: The chemical formula that hydroiodic acid (aq. Hydrogen iodide) is HI. That is molar fixed is 127.91 g/mol. Hydrogen iodide is the gaseous form, when hydroiodic acid is the aqueous systems of HI. They space both interchangeable. Hello is a straightforward diatomic molecule v the listed below structure:


Hydrogen iodide is polarized due to the fact that of the electronegativity that the iodide. Due to the huge size that the iodide ion, the an adverse charge is spread resulting in a weaker H-I bond. This permits the H+ to be conveniently dissociated and hence, hello is a stronger acid 보다 HCl, HBr and also HF.


Preparation: Hydroiodic mountain is ready commercially by the reaction the iodine (I2) v hydrazine, providing hydrogen iodide and also nitrogen gas.

2 I2 + NH2NH2 → 4 hello + N2

Hydroiodic mountain is additionally prepared by bubbling hydrogen sulfide gas through an aqueous solution of iodine.

H2S + I2 → 2 hello + S

At the end of the reaction, hi is distilled to provide hydroiodic acid in the desired concentrations.

Physical properties: Hydrogen iodide is a colorless gas v an acrid odor the is conveniently soluble in water to offer hydroiodic acid. "Concentrated" hydroiodic acid is usually 48-57% hi in water. Its precise physical nature (boiling point, melting point and density) count on the concentration of hello in the aqueous solution.

Chemical properties: Hydroiodic acid is a solid and reactive acid. It should be used carefully due to its an effective reactivity. It have the right to react violent with metal powders, ammonia, etc., to create fire and also explosions. That is highly corrosive, and reacts strongly through bases. HI also decomposes on heater to generate toxicity fumes, and gets oxidized rapidly in air.

Uses: one of the most typical uses of hello is to type alkyl iodides, vital class of essential compounds, by reaction HI v alkenes or major alcohols. Hydroiodic acid is likewise a typical reducing agent because that various commercial purposes.

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Health hazards/ wellness effects: The hi gas is toxic by inhalation and also highly irritating come skin, eyes and mucous membranes. Hydroiodic mountain can reason severe skin burns and also eye damage, and is very toxic if inhaled, ingested or soaked up through skin. Irreversible exposure in short concentrations can also cause adverse health and wellness effects.