Do bonds break during a phase change?

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.
D

deleted647690

I came across an answer in my TBR book that says "While it is true that allotropes have different interatomic bonding, bonds are not broken during a phase change.."
I did not know this. But many sources that I looked at online explain phase changes in terms of bonds breaking....

Members don't see this ad.
 
I mean, think liquid to gas. Intermolecular bonds have to break to free up the individual gas molecules.
 
H-bonds do break when the molecules undergo a phase change, but covalent bonds do not break. That is the source of the confusion. Covalent bonds have high BDEs (usually in the 100 kcal range for nonpolar bonds) and are hard to break. H-bonds have low BDEs (in the range of 5 kcals or so) and so do break during a phase change.
 
  • Like
Reactions: 1 user
Top