Suppose a hydrogen bond in water has an energy of about 2 kcal/mol. Suppose a "made" bond is the ground state in a two.state model and a "broken" bond is the excited state. At T = 300K, what fraction of hydrogen bonds are broken?

 

Interesting, I've never come across this sort of question in my chemistry classes however, what equations were you taught in class? This is probably just a plug and play.

 

The solution, I believe, is reached in the same way you calculate the proportion of chair/boat configurations for 6-membered rings at various temperatures. Just look up equilibrium constant and Gibbs free energy.

John