The Hydrogen-Bond Strength of Ice

PAULING 1 estimated the strength of the hydrogen bond in water by taking the heat of sublimation of ice and allowing a reasonably guessed value for the dispersion contribution to the bond, and arrived at a value of 4.5 kcal./ N bonds, where N is Avogadro's number. Later, Grunberg and Nissan 2 calculated the dispersion contribution from surface tension data by assuming that the dispersion energy equalled the work of cohesion as defined by Harkins 3 . By taking the internal latent heat of vaporization of water plus the heat of fusion as equal to the internal heat of sublimation of ice and subtracting the work of cohesion, a value of 3.71 kcal./ N was obtained. They also made a calculation from the dipole moment (taking certain evidence from viscosity data into account) and found a value of 3.23 kcal./ N . Recently, I 4 formulated a relationship between the elastic constants of cellulose sheets and the strength of the hydrogen bond. The same relationship should apply to ice and therefore it should be possible to calculate the bond energy from the modulus of elasticity.