A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle.In most cycles it undergoes phase transitions from a liquid to a gas and back again.Many working fluids have been used for such purposes. R-401A is a HCFC zeotropic blend of R-22, R-152a, and R-124. 2  It is designed as a replacement for R-12. 3  R-404A is a HFC nearly azeotropic  blend of 52 wt.% R-143a, 44 wt.% R-125, and 4 wt.% R-134a. 4  It is designed as a replacement of R-22 and R-502 CFC.
The temperature of the ice will continue to decrease until it reaches the same temperature as the outside air which is 20 F. Liquid water has more energy than frozen water. When water freezes it gives up some of the water's energy. This energy that is given up is the latent heat of freezing.
Heat provides the energy needed to change a solid into a liquid. Heat energy is added to break the bonds between molecules in a solid. The amount of heat needed to cause a solid to turn to a liquid is called the melting point. Continue Reading. By removing heat energy, a liquid can be turned back into a solid. This is called freezing. Generally, matter cycles between the liquid and solid state by the removal or addition of heat energy. Intense heating of a liquid causes vaporization and creates a gas. Solids can skip the melting phase and turn into a gas by a process known as sublimation.