## Abstract

A simple model for the anomalous excess thermodynamic properties of water is described which, without postulation of molecular species, leads to a "two-state" thermodynamic description as zeroth-order approximation. The model, which is consistent with the common notion that water is best regarded as a disrupted tetrahedral network, involves the concept of elementary configurational excitations of an initially totally connected random network ground-state quasi-lattice. The zeroth-order equations allow a better description of the configuration heat capacity of water and its temperature dependence than those achieved by "mixture model" two-state equations. The model also appears consistent with proton magnetic resonance chemical shift data and with the broad-band aspects of infrared and Raman spectral findings. With an additional postulate concerning the cooperative nature of the flow process, but without additional parameters, the non-Arrhenius temperature dependence of viscosity and other relaxation processes is correctly described and the negative "volume of activation" is accounted for. A glass transition near 159°K is predicted. It is suggested that first-order corrections to the model, which would take into account the cooperative aspects of hydrogen bonding in water suggested by recent quantum-mechanical calculations on static groups, effect mainly the low temperature properties. Their inclusion may lead to an account of the accelerating negative thermal expansion coefficient observed for highly supercooled water.

Original language | English (US) |
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Pages (from-to) | 3698-3705 |

Number of pages | 8 |

Journal | Journal of physical chemistry |

Volume | 75 |

Issue number | 24 |

State | Published - Dec 1 1971 |

Externally published | Yes |

## ASJC Scopus subject areas

- Engineering(all)
- Physical and Theoretical Chemistry