How to explain unusual properties of supercritical water

Background

A supercritical fluid [SCF] is any substance at a temperature and pressure above its critical point [ Water ->647.096 K, >22.064 MPa ] . Above critical point gas and liquid exist in one phase. Following are some key properties of SCF: [1]Gas and liquid has same density, in case of water, about 0.32 g/cc [2] Small changes in pressure or temperature result in large changes in density [3] SCF water is a poor solvent for electrolytes [4] An excellent solvent for non-polar molecules [5] Viscosity decreases [6] Dielectric decreases [7] Auto-dissociation of water increases [8] Supercritical water has no surface tension with its gas or liquid phase or any other supercritical phase as no such interfaces exist [9] Above 647.096 K, the critical temperature of water, water vapor cannot be liquefied by increasing pressure.

Explanation

Hypothesis

“ Above critical point both gas particle and liquid particles have near zero or near equal intra and intermolecular forces acting on them”.

Proof of hypothesis

Gas and liquid have same density – Near zero / near equal intermolecular forces produce similar molecular packing in both so they have same density

Becomes a nonpolar solvent- Since no intra and no intermolecular forces exist, the surface tension of supercritical water is zero. At low / near zero surface tension the supercritical water becomes a solvent for nonpolar compounds and does not dissolve polar ionic compounds

For same above reasons, viscosity and dielectric decreases in supercritical water.

Viscosity decreases in supercritical water because the molecules do not exist as cluster . Dielectric decreases as supercritical molecules are nonpolar.

Latent heat or heat of vaporization is zero - Nonexistence of intra/intermolecular forces above critical point do not require any additional heat to break bonds

Above critical point water vapor cannot be liquefied by increasing pressure - Nonexistence of intra/intermolecular forces above critical point do not allow transformation of vapor to liquid with increased pressure.