01 What is Ethanol?
The alcohol in alcoholic drinks. Acts on GABA receptors (inhibitory) and NMDA receptors (excitatory) in the brain, producing sedation. Produced by fermentation of sugars by yeast, or industrially by hydration of ethylene.
02 Why It Matters
Ethanol is both a major fuel (E10/E85 blends, bioethanol) and the active compound in alcoholic drinks. Its ability to mix with both water and oils makes it an excellent solvent for perfumes, medicines, and disinfectants (70% v/v is the optimal antibacterial concentration).
03 Structure and Bonding
Shape: Tetrahedral at C atoms; bent O-H
Bonds: C-C, C-H, C-O single bonds; O-H with H-bonding
Polarity: Polar (hydroxyl group) - The asymmetry of the molecule means bond dipoles don't cancel, giving the molecule a net dipole moment. This affects its solubility, boiling point, and interactions with other molecules.
70% ethanol kills bacteria more effectively than 99% - the water is needed to denature proteins. Pure ethanol dehydrates bacteria's outer membrane too quickly, causing them to form a protective crust.