Freezing

(noun)

Freezing or solidification is a phase transition in which a liquid turns into a solid when its temperature is lowered to its freezing point.

Related Terms

Examples of Freezing in the following topics:

  • Freezing Point Depression

    • Freezing point depression is the phenomena that describes why adding a solute to a solvent results in the lowering of the freezing point of the solvent.
    • The freezing point depression can also be explained in terms of vapor pressure.
    • In this equation, $\Delta T_f$ is the freezing point depression, Kf is the freezing point depression constant, and i is the van 't Hoff factor.
    • The value of 0.93 oC is the change in the freezing point.
    • Discuss the effects of a solute on the freezing point of a solvent

  • Liquid to Solid Phase Transition

    • Freezing is a phase transition in which a liquid turns into a solid when its temperature is lowered to its freezing point.
    • Freezing, or solidification, is a phase transition in which a liquid turns into a solid when its temperature is lowered to or below its freezing point.
    • All known liquids, except helium, freeze when the temperature is low enough.
    • Most liquids freeze by crystallization, the formation of a crystalline solid from the uniform liquid.
    • But heat must be continually removed from the freezing liquid, or the freezing process will stop.

  • Crystalline Solids

    • However, if the solid melts, or the liquid freezes, a discontinuity occurs and the temperature of the sample remains constant until the phase change is complete.
    • For a given compound, this temperature represents its melting point (or freezing point), and is a reproducible constant as long as the external pressure does not change.
    • Now it is well known that the freezing point of a solvent is lowered by a dissolved solute, e.g. brine compared with water.
    • Melting or freezing takes place over a broad temperature range and there is no true eutectic point.

  • Physical and Chemical Properties of Matter

    • For example, the freezing point of a substance is a physical property: when water freezes, it's still water (H2O)—it's just in a different physical state.

  • Temperature

    • They do not generate a number: they do not tell us that water freezes at 0 °C, or that it boils at 100 °C.
    • Isaac Newton proposed a thermometer with a scale of 12 degrees between the freezing and boiling points of water.
    • Anders Celsius proposed a 100 degree scale for the difference between freezing and boiling of water, and after a few minor adjustments, the Celsius, or centigrade, system was also widely adopted.
    • Celsius is a scale and unit of measurement for temperature where 0 °C is the freezing point of water.

  • Volume and Density

    • At 0 °C, water freezes to ice and floats.
    • The implications of this simple fact are enormous: when a lake freezes, ice crusts at the surface and insulates the liquid below from freezing, while at the same time allowing the colder water (with a temp of approx. 4 °C and a high density) to sink to the bottom.

  • Major Features of a Phase Diagram

    • The green line marks the freezing point (or transition from liquid to solid), the blue line marks the boiling point (or transition from liquid to gas), and the red line shows the conditions under which a solid can be converted directly to a gas (and vice-versa).

  • Solid to Gas Phase Transition

    • Even ice has a measurable vapor pressure near its freezing point, as evidenced by the tendency of snow to evaporate in cold dry weather.

  • Oxidation of Alcohols by DMSO

    • Co-solvents such as methylene chloride or THF are needed, since pure DMSO freezes at 18º.

  • Three States of Matter

    • A solid can transform into a liquid through melting, and a liquid can transform into a solid through freezing.
    • The video also discusses melting, vaporization, condensation, and freezing.