Ethylene Glycol (HOCH2CH2OH)
* Strong Hydrogen Bonding: Ethylene glycol has two hydroxyl groups (-OH) per molecule. These hydroxyl groups are capable of forming both donor and acceptor hydrogen bonds.
* Donor: The hydrogen atom in the -OH group can form a hydrogen bond with the oxygen atom of another ethylene glycol molecule.
* Acceptor: The oxygen atom in the -OH group can accept a hydrogen bond from the hydrogen atom of another ethylene glycol molecule.
* Result: Ethylene glycol forms extensive hydrogen bonding networks in the liquid and solid states, contributing to its high boiling point and viscosity.
Methanol (CH3OH)
* Hydrogen Bonding: Methanol has one hydroxyl group (-OH) per molecule, allowing it to form hydrogen bonds.
* Donor: The hydrogen atom in the -OH group can form a hydrogen bond with the oxygen atom of another methanol molecule.
* Acceptor: The oxygen atom in the -OH group can accept a hydrogen bond from the hydrogen atom of another methanol molecule.
* Result: Methanol forms hydrogen bonds, though not as extensive as ethylene glycol, contributing to its higher boiling point than similar hydrocarbons.
Formaldehyde (H2CO)
* No Hydrogen Bonding: Formaldehyde lacks a hydroxyl group (-OH) or any other group with a highly electronegative atom bonded to hydrogen. Therefore, it cannot form hydrogen bonds.
* Result: Formaldehyde's lack of hydrogen bonding contributes to its relatively low boiling point and gaseous state at room temperature.
Summary
| Molecule | Hydrogen Bonding | Explanation |
|-------------------|--------------------|-------------------------------------------------------|
| Ethylene Glycol | Strong | Two hydroxyl groups allow for extensive hydrogen bonding |
| Methanol | Present | One hydroxyl group allows for hydrogen bonding |
| Formaldehyde | None | No hydroxyl group, no hydrogen bonding capability |
