Hydration Reaction Definition

Blue liquid solutions in flasks
A hydration reaction is a chemical reaction with water.

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A hydration reaction is a chemical reaction where a hydrogen and hydroxyl ion is attached to a carbon in a carbon double bond. Generally, one reactant (usually an alkene or alkyne) reacts with water to yield ethanol, isopropanol, or 2-butanol (all alcohols) are a product.

Formula and Example

The general formula for a hydration reaction is:
RRC=CH2 in acid → RRC(-OH)-CH3

An example is the hydration reaction of ethylene oxide to produce ethylene glycol:

C2H4O + H2O → HO-CH2CH2-OH