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

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Formula and structure: The chemical formula the hydroiodic acid (aq. Hydrogen iodide) is HI. The molar mass is 127.91 g/mol. Hydrogen iodide is the gaseous form, while hydroiodic mountain is the aqueous systems of HI. They are both interchangeable. Hello is a basic diatomic molecule through the below structure:


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


Preparation: Hydroiodic acid is all set commercially by the reaction the iodine (I2) v hydrazine, offering hydrogen iodide and nitrogen gas.

2 I2 + NH2NH2 → 4 hello + N2

Hydroiodic mountain is also prepared by bubbling hydrogen sulfide gas v an aqueous systems of iodine.

H2S + I2 → 2 hello + S

At the end of the reaction, hi is distilled to offer hydroiodic mountain in the wanted concentrations.

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

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

Uses: one of the most common uses of hello is to type alkyl iodides, an essential class of organic compounds, by reacting HI with alkenes or major alcohols. Hydroiodic acid is also a common reducing agent because that various industrial purposes.

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Health hazards/ health effects: The hello gas is toxic by inhalation and highly irritating to skin, eyes and also mucous membranes. Hydroiodic mountain can reason severe skin burns and eye damage, and is extremely toxic if inhaled, ingested or absorbed through skin. Irreversible exposure in low concentrations can additionally cause adverse wellness effects.