Hydroxyl Group — Definition, Formula, Properties & Uses | AllChemicals | AllChemicals

Q: What is the formula for Hydroxyl Group?

The formula or notation for Hydroxyl Group is: R-OH: -OH group attached to organic carbon (alcohol or phenol)

Formula / Notation	R-OH: -OH group attached to organic carbon (alcohol or phenol)
Also Known As	OH group, hydroxyl functional group, alcohol group, hydroxyl substituent

What is Hydroxyl Group?

The functional group -OH consisting of an oxygen atom bonded to a hydrogen atom. The hydroxyl group makes compounds more water-soluble and more reactive. It is found in alcohols, phenols, and carboxylic acids, imparting acidic or neutral character depending on the compound.

Formula & Notation

R-OH: -OH group attached to organic carbon (alcohol or phenol)

Other Names / Synonyms: OH group, hydroxyl functional group, alcohol group, hydroxyl substituent

Properties & Characteristics

The hydroxyl group (-OH) is a functional group consisting of one oxygen atom bonded to one hydrogen atom, covalently attached to an organic or inorganic moiety. In organic compounds: attached to carbon gives alcohols (R-OH) or phenols (Ar-OH). In inorganic chemistry: metal hydroxides (NaOH, Ca(OH)₂) contain OH⁻ ions. The hydroxyl group is polar (capable of hydrogen bonding) and confers water solubility to organic molecules. pKa of aliphatic alcohols ~16-18; phenols ~10; water: 15.7.

Uses & Applications

Hydroxyl groups are present in alcohols (solvents, fuels, pharmaceuticals), carbohydrates (sugars, cellulose), phenols (antioxidants, disinfectants), and nucleosides (ribose in RNA has 2'OH). Hydroxyl groups are sites for esterification, etherification, oxidation, and hydrogen bonding in materials science and drug design.

Safety Information

Alcohols (methanol: toxic, optic nerve damage; ethanol: CNS depressant; isopropanol: narcotic) vary in toxicity. Phenol is highly toxic via skin absorption. Hydroxyl groups on drugs contribute to metabolic conjugation (glucuronide) reducing activity. High-purity anhydrous alcohols are highly flammable.

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

Key Facts

Term Hydroxyl Group

Formula R-OH: -OH group attached to organic carbon (alcohol or phenol)

Index All "H" terms

Synonyms OH group, hydroxyl functional group, alcohol group, hydroxyl substituent

Frequently Asked Questions

What is Hydroxyl Group?

The functional group -OH consisting of an oxygen atom bonded to a hydrogen atom. The hydroxyl group makes compounds more water-soluble and more reactive. It is found in alcohols, phenols, and carboxylic acids, imparting acidic or neutral character depending on the compound.

What is Hydroxyl Group used for?

Is Hydroxyl Group hazardous?

What is the formula for Hydroxyl Group?

More "H" Terms

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 Halogenation C-X + Cl₂/Br₂ (hv or AlCl₃) → C-X(halogen); EAS or radical pathway Halogens Hard Acid Hard acid: small, highly charged, low polarisability (e.g., H⁺, Mg²⁺, Al³⁺)

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