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A cooling curve of naphthalene from liquid to solid. A cooling curve is a line graph that represents the change of phase of matter, typically from a gas to a solid or a liquid to a solid. The independent variable (X-axis) is time and the dependent variable (Y-axis) is temperature. [1] Below is an example of a cooling curve used in castings.
There are two types of continuous cooling diagrams drawn for practical purposes. Type 1: This is the plot beginning with the transformation start point, cooling with a specific transformation fraction and ending with a transformation finish temperature for all products against transformation time for each cooling curve.
Phase transitions commonly refer to when a substance transforms between one of the four states of matter to another. At the phase transition point for a substance, for instance the boiling point, the two phases involved - liquid and vapor, have identical free energies and therefore are equally likely to exist.
The upper curve is the line of liquidus, and the lower curve is the line of solidus. In chemistry , materials science , and physics , the liquidus temperature specifies the temperature above which a material is completely liquid, [ 2 ] and the maximum temperature at which crystals can co-exist with the melt in thermodynamic equilibrium .
Cooling Agent Organic Solvent or Inorganic Salt T (°C) Notes Dry ice: p-Xylene +13 [1] Dry ice: p-Dioxane +12 Dry ice: Cyclohexane +6 Dry ice: Benzene +5 Dry ice: Formamide +2 Ice: Water: 0 Ice: Ammonium chloride-5 0.3 to 1 ratio of salt to ice. Liquid N 2: Aniline-6 Ice: Sodium thiosulfate pentahydrate-8 1.1 to 1 ratio of salt to ice. Ice ...
A cooling bath or ice bath, in laboratory chemistry practice, is a liquid mixture which is used to maintain low temperatures, typically between 13 °C and −196 °C. These low temperatures are used to collect liquids after distillation , to remove solvents using a rotary evaporator , or to perform a chemical reaction below room temperature ...
Doppler cooling is the most common method of laser cooling. Sympathetic cooling is a process in which particles of one type cool particles of another type. Typically, atomic ions that can be directly laser-cooled are used to cool nearby ions or atoms. This technique allows the cooling of ions and atoms that cannot be laser-cooled directly. [47]
Thus, the liquid–liquid critical point in a two-component system must satisfy two conditions: the condition of the spinodal curve (the second derivative of the free energy with respect to concentration must equal zero), and the extremum condition (the third derivative of the free energy with respect to concentration must also equal zero or ...