kasse said:Homework Statement
Explain the boiling points of HF, HCl, HBr nd HI
The Attempt at a Solution
The boiling points are:
HF: 20 C
HCl: -85 C
HBr: -67 C
HI: -35 C
The hydrogen bondings between H and F are stronger than other hydrogen bondings. Therefore HF has the highest boiling point. But then I'd expect the order to be HCl > HBr > HI; not the opposite. How can that be explained?
Kushal said:what are the requirements for an H-bond to be formed?
The presence of hydrogen bonding between molecules increases the boiling point of a substance. This is because hydrogen bonds are stronger intermolecular forces compared to dipole-dipole interactions or London dispersion forces, and therefore require more energy to break.
No, hydrogen bonding can only occur between molecules that have a hydrogen atom bonded to an electronegative atom such as nitrogen, oxygen, or fluorine. This is due to the large difference in electronegativity between hydrogen and these atoms, creating a polar covalent bond.
Aside from increasing the boiling point, hydrogen bonding can also affect other physical properties such as surface tension, viscosity, and solubility. This is because hydrogen bonds between molecules create a stronger attraction and can affect their arrangement and movement.
Yes, hydrogen bonding can affect the reactivity of a substance. For example, molecules that can form hydrogen bonds are more likely to undergo reactions with other molecules that can also form hydrogen bonds, as these bonds can be easily broken and reformed during a reaction.
No, there are other intermolecular forces that are stronger than hydrogen bonding, such as ionic bonds and covalent bonds. However, among the types of intermolecular forces, hydrogen bonding is one of the strongest and can have a significant impact on the physical and chemical properties of substances.