Does methanol form hydrogen bonds with itself or water molecules
Methanol (CH3OH) can form hydrogen bonds with itself as well as with water molecules.
When methanol molecules interact with each other, the hydrogen atom on the hydroxyl group (-OH) of one methanol molecule can form a hydrogen bond with the oxygen atom on the hydroxyl group of another methanol molecule. This is because the hydrogen is partially positive due to its bond with the more electronegative oxygen, and the oxygen has lone pairs of electrons, making it slightly negative. The positive hydrogen is attracted to the negative oxygen of a neighboring molecule, resulting in a hydrogen bond.
Similarly, when methanol is mixed with water, the hydrogen atoms of water (H2O) can form hydrogen bonds with the oxygen of the methanol hydroxyl group. Conversely, the hydrogen of the methanol hydroxyl group can form hydrogen bonds with the oxygen atoms of water molecules. The ability to form hydrogen bonds with water is what makes methanol miscible with water in all proportions.
Hydrogen bonding greatly affects the physical properties of methanol, including its boiling point, solubility, and specific heat capacity, among others. These properties are also the reason why methanol can dissolve many polar substances and behave as an antifreeze, solvent, and fuel.