Effect of intermolecular hydrogen bonding

In summary, Hydrogen bonding between water molecules results in liquid water. The boiling points of water molecules decrease as the hydrogen bonding between them gets stronger.
  • #1
gracy
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Effect of intermolecular hydrogen bonding is as follows
hydrogen bonding.png

I don't understand one point i.e how occurrence of liquid state is associated with intermolecular hydrogen bonding
as intermolecular hydrogen bonding helps in closed packing of molecules it should give rise to solid state.
 
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  • #2
gracy said:
it should give rise to solid state.

And it finally does when the temperature gets low enough. But even when water is in the liquid form some molecules are linked by hydrogen bonds. Not all, and there is no lattice going throughout the liquid, but locally clusters of several molecules can be quite ordered.
 
  • #3
gracy said:
Effect of intermolecular hydrogen bonding is as follows
View attachment 82608
I don't understand one point i.e how occurrence of liquid state is associated with intermolecular hydrogen bonding
as intermolecular hydrogen bonding helps in closed packing of molecules it should give rise to solid state.

What you are looking at is probably a list of periodic trends for the oxygen family hydrides (H2O, H2S, H2Se, etc...) As you move up the column, the boiling points decrease. H2S is a gas at room temperature, you would predict (based upon the trend) that H2O would also be a gas, and have an even lower boiling point. The fact is that it is a liquid at room temperature and it has a very high boiling point. The reason for both of these observations is attibuted to the relatively strong interactions between the water molecules, compared with H2S, etc. and the rest of the members of the series. These strong interactions are called hydrogen bonds.
 
  • #4
Borek said:
And it finally does when the temperature gets low enough. But even when water is in the liquid form some molecules are linked by hydrogen bonds. Not all, and there is no lattice going throughout the liquid, but locally clusters of several molecules can be quite ordered.

Plus anything you put into the water, polar or non polar, changes these structures or creates others. Around proteins for instance sometimes some water molecules are immobilized enough to be characterized as fixed structures by X-ray crystallography. Elementary and semi-elementary texts focus possibly overmuch on molecules alone when it is molecules in their solvent environment that are the thing to explain or the thing that explains IMHO. In short - never forget the solvent!
 
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FAQ: Effect of intermolecular hydrogen bonding

What is intermolecular hydrogen bonding?

Intermolecular hydrogen bonding is a type of chemical bond that occurs between a hydrogen atom and an electronegative atom (such as oxygen, nitrogen, or fluorine) in a different molecule. It is a weak bond, but can have a significant impact on the physical properties and behavior of molecules.

What are the effects of intermolecular hydrogen bonding on a molecule?

Intermolecular hydrogen bonding can affect a molecule in several ways. It can increase the boiling point and surface tension of a liquid, making it more difficult to break apart the molecules. It can also affect the solubility of a substance, as well as the strength and stability of a crystal lattice in a solid state.

How does intermolecular hydrogen bonding contribute to the properties of water?

Water is a molecule that exhibits intermolecular hydrogen bonding, which is why it has unique properties such as high boiling point, surface tension, and the ability to dissolve many substances. The hydrogen bonds between water molecules also contribute to its cohesive and adhesive properties, allowing it to form droplets and cling to other surfaces.

Can intermolecular hydrogen bonding be broken?

Yes, intermolecular hydrogen bonds can be broken. They are weaker than covalent bonds, so they can be disrupted by changes in temperature, pressure, or the presence of other molecules. This is why substances like water can change from a liquid to a gas (vaporization) or a solid (freezing) when these bonds are broken.

How does intermolecular hydrogen bonding affect the structure of biomolecules?

Intermolecular hydrogen bonding plays a crucial role in the structure and function of biomolecules such as DNA, proteins, and carbohydrates. These bonds help to stabilize the specific shapes and conformations of these molecules, which are essential for their biological functions. They also contribute to the interactions between biomolecules, allowing them to form complex structures and carry out vital processes in living organisms.

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