H

Hydrogen cyanide

IUPAC: formonitrile

CHN Inorganic Compounds CAS 74-90-8
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Quick Reference
Formula / NotationCHN
CAS Number74-90-8
Molecular Weight27.025
Melting Point7 °F (96%) (NIOSH, 2024)
Boiling Point78 °F at 760 mmHg (96%) (NIOSH, 2024)
Density0.69 (NIOSH, 2024) - Less dense than water; will float
SolubilityMiscible (NIOSH, 2024)
AppearanceHydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide is a clear colorless aqueous solution of a gas. Has a faint odor of almonds. Can evolve hydrogen cyanide gas, which is (b...
Also Known Asformonitrile; hydrocyanic acid; Formonitrile; Prussic acid; Blausaeure; Cyanwasserstoff; Formic anammonide; Cyclon; Evercyn; 74-90-8
CategoryInorganic Compounds

What is Hydrogen cyanide?

Hydrogen cyanide (HCN) and cyanide salts (CN salts) can cause male reproductive toxicity according to The Environmental Protection Agency (EPA).

Formula & Notation

CHN

IUPAC Name: formonitrile

Other Names / Synonyms: formonitrile; hydrocyanic acid; Formonitrile; Prussic acid; Blausaeure; Cyanwasserstoff; Formic anammonide; Cyclon; Evercyn; 74-90-8

Properties & Characteristics

Appearance: Hydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide is a clear colorless aqueous solution of a gas. Has a faint odor of almonds. Can evolve hydrogen cyanide gas, which is (b.... Molecular formula: CHN. Molecular weight: 27.025 g/mol. Boiling point: 78 °F at 760 mmHg (96%) (NIOSH, 2024). Melting point: 7 °F (96%) (NIOSH, 2024). Density: 0.69 (NIOSH, 2024) - Less dense than water; will float. Solubility: Miscible (NIOSH, 2024). Vapor pressure: 630 mmHg (NIOSH, 2024). LogP: 0.1.

Physical Data

PropertyValue
Melting Point7 °F (96%) (NIOSH, 2024)
Boiling Point78 °F at 760 mmHg (96%) (NIOSH, 2024)
Density0.69 (NIOSH, 2024) - Less dense than water; will float
Molecular Weight27.025
SolubilityMiscible (NIOSH, 2024)
AppearanceHydrocyanic acid, aqueous solution, with not more than 20% hydrogen cyanide is a clear colorless aqueous solution of a gas. Has a faint odor of almonds. Can evolve hydrogen cyanide gas, which is (b...

Uses & Applications

Used in industrial processes, materials science, semiconductor manufacture, ceramics, or as a catalyst.

Safety Information

May be corrosive, toxic, or an oxidising agent. Handle in well-ventilated area. Consult SDS before use.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Hydrogen cyanide
Formula CHN
CAS Number 74-90-8
Molecular Weight 27.025
Category Inorganic Compounds
Index All "H" terms
Synonyms formonitrile; hydrocyanic acid; Formonitrile; Prussic acid; Blausaeure; Cyanwasserstoff; Formic anammonide; Cyclon; Evercyn; 74-90-8

Frequently Asked Questions

Hydrogen cyanide (HCN) and cyanide salts (CN salts) can cause male reproductive toxicity according to The Environmental Protection Agency (EPA).

More "H" Terms

1-Hexanol C6H14O 2-Hydroxyethyl methacrylate C6H10O3 4-Hydroxybenzaldehyde C7H6O2 Haber Process N₂ + 3H₂ ⇌ 2NH₃ | ΔH = −92 kJ/mol Hafnium Hf Half Cell Half Life Half-Cell E = E° − (RT/nF)lnQ Half-Life A(t) = A₀e^(−λt); t½ = ln2/λ Half-Reaction Halide X⁻ (e.g., F⁻, Cl⁻, Br⁻, I⁻) Halogen F₂, Cl₂, Br₂, I₂, At; Group 17; ns²np⁵ valence configuration
View all "H" terms →
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Editorial standards: Chemical data is sourced from peer-reviewed literature, CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA, and IAEA. For educational purposes only — always consult official SDS documentation and qualified professionals before handling chemicals.

AllChemicals.info — The Online Chemical Glossary | https://allchemicals.info/chemical/hydrogen-cyanide

For educational purposes only. Verify all information before use.