Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is

Sublimation temperature of dry ice (solid CO₂) is __________ °C.

The equation relating E, P, V and T which is true for all substanes under all conditions is given by $${\left( {\frac{{\partial {\text{E}}}}{{\partial {\text{V}}}}} \right)_{\text{T}}} = {\text{T}} \cdot {\left( {\frac{{\partial {\text{P}}}}{{\partial {\text{T}}}}} \right)_{\text{H}}} - {\text{P}}{\text{.}}$$      This equation is called the

Henry's law is closely obeyed by a gas, when its __________ is extremely high.

If an ideal solution is formed by mixing two pure liquids in any proportion, then the __________ of mixing is zero.