Here's the balanced chemical equation for the reaction:
H₃BO₃ + 3C₂H₅OH ⇌ B(OC₂H₅)₃ + 3H₂O
Mechanism:
The reaction proceeds through a series of steps involving the following:
1. Protonation of ethanol: The hydroxyl group of ethanol gets protonated by orthoboric acid, forming an oxonium ion.
2. Nucleophilic attack: The oxygen atom of the ethanol molecule attacks the boron atom in orthoboric acid, forming a tetrahedral intermediate.
3. Elimination of water: A water molecule is eliminated from the tetrahedral intermediate, resulting in the formation of triethyl borate.
Key points:
* The reaction is reversible, meaning that triethyl borate can react with water to form orthoboric acid and ethanol again.
* The reaction is typically carried out in the presence of a catalyst, such as concentrated sulfuric acid.
* Triethyl borate is a colorless liquid with a pleasant odor and is used as a solvent, fuel additive, and in the synthesis of other boron compounds.
Overall, the reaction of orthoboric acid with ethanol is a classic example of esterification, resulting in the formation of triethyl borate and water.
