melting points

[Andrew Jang 4D]

why is H2O's melting point 0 degrees C while H2S has a melting point of -86 degrees C?

[Andrew Pfeiffer 2E]

Water molecules undergo intense hydrogen bonding between the oxygen and hydrogen atoms. This makes it significantly harder for the intermolecular forces to be overcome to melt ice. Conversely, H₂S has dipole-dipole interactions (S being negative and H positive). While these dipole-dipole interactions are important, they are not nearly as strong as the hydrogen bonding in H₂O, and hence, the lower melting point.

[IScarvie 1E]

Another way to think about it is that O is more electronegative than S, so its dipole moments are more dramatic than H2S's. The positive and negative ends form stronger bonds because of it.

[905416023]

So hydrogen bonds make the molecule harder to break apart? So then they have a higher boiling point?

[Rory Simpson 2F]

So hydrogen bonds make the molecule harder to break apart? So then they have a higher boiling point?

Yes, the strength of hydrogen bonds causes the molecules to have a greater intermolecular attraction which increases their melting and boiling points.

[Shail Avasthi 2C]

Hydrogen bonds are stronger than dipole/dipole or induced dipole/induced dipole interactions. H2O has the ability to hydrogen bond with itself because of the H-O bond, while H2S cannot. This accounts for H2O's higher melting point.

[Shrayes Raman]

H20 has rather strong hydrogen interactions that H2S does not