freezing point depression

(noun)

Adding a solute to a solvent decreases the temperature at which the liquid solvent becomes a solid.

Related Terms

Examples of freezing point depression in the following topics:

  • Freezing Point Depression

    • Freezing point depression is a colligative property observed in solutions, brought on by the introduction of solute molecules to a solvent.
    • 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 freezing point depression constant changes depending on the solvent, and the van 't Hoff factor accounts for the number of particles that a dissolving solute creates in solution.

  • 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.
    • For most substances, the melting and freezing points are the same temperature; however, certain substances possess different solid-liquid transition temperatures.
    • The melting point of water at one atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K), and in the presence of nucleating substances the freezing point of water is close to the melting point.
    • But heat must be continually removed from the freezing liquid, or the freezing process will stop.

  • Crystalline Solids

    • 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.
    • If two crystalline compounds (A & B) are thoroughly mixed, the melting point of that mixture is normally depressed and broadened, relative to the characteristic sharp melting point of each pure component.
    • The lowest mixture melting point, e, is called the eutectic point.
    • Melting or freezing takes place over a broad temperature range and there is no true eutectic point.

  • Farenheit Scale

    • In the Fahrenheit scale, the freezing of water is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees.
    • On this scale, water's freezing point is defined to be 32 degrees, while water's boiling point is defined to be 212 degrees.
    • The Fahrenheit system puts the boiling and freezing points of water exactly 180 degrees apart.
    • Therefore, a degree on the Fahrenheit scale is 1/180 of the interval between the freezing point and the boiling point.
    • On the Celsius scale, the freezing and boiling points of water are 100 degrees apart.

  • Phase Changes and Energy Conservation

    • The opposite happens when water freezes.
    • If that amount of energy is added to a mole of that substance at boiling or freezing point, all of it will melt or boil, but the temperature won't change.
    • At this point, there is a mixture of both ice and water.
    • The curve ends at a point called the critical point, because at higher temperatures the liquid phase does not exist at any pressure.
    • In this typical phase diagram of water, the green lines mark the freezing point, and the blue line marks the boiling point, showing how they vary with pressure.

  • Change from another angle

    • ., ‘Kurt Lewin's change theory in the field and in the classroom: Notes toward a model of managed learning') Since good habits are recognized as being just as difficult to break as bad habits, the analogy the two men make is to unfreeze bad habits and freeze improved habits once they've been established.
    • Examples of how some businesses get their employees to admit that waste reduction is needed is to involve them in estimating the amount (and cost) of the waste the business produces, analyzing energy and fuel consumption, offering carbon emission estimates, and/or pointing out garbage levels and costs.
    • Freeze new behaviours.

  • Explaining Mood Disorders

    • While everyone experiences negative mood at some point in their lives, mood disorders affect an individual's capacity to function in daily life.
    • When most people think of mood disorders, they typically think of depression (also called major depressive disorder and clinical depression) and bipolar disorder.
    • Dysthymia and major depression naturally have many symptoms in common, including depressed mood, disturbed sleep, low energy, and poor concentration.
    • Cognitive-behavioral therapy has been shown to be a possible treatment for depression.
    • Bipolar disorder is characterized by cycles of depressive and manic episodes.

  • Budget Cuts

    • Reaganomics was the subject of debate with supporters pointing to improvements in certain key economic indicators as evidence of success, and critics pointing to large increases in federal budget deficits and the national debt.
    • Unemployment peaked at 10.8% monthly rate in December 1982—higher than any time since the Great Depression—then dropped during the rest of Reagan's presidency.
    • These views were exacerbated by the fact that Reagan's economic regimen included freezing the minimum wage at $3.35 an hour, slashing federal assistance to local governments by 60%, cutting the budget for public housing and Section 8 rent subsidies in half, and eliminating the antipoverty Community Development Block Grant program.

  • Latent Heat

    • Conversely, water freezes in an ice tray cooled by lower-temperature surroundings .
    • Conversely, energy is released during freezing and condensation, usually in the form of thermal energy.
    • Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.
    • Even more energy is required to vaporize water; it would take 2256 kJ to change 1 kg of liquid water at the normal boiling point (100ºC at atmospheric pressure) to steam (water vapor).
    • That same energy must be removed for freezing to take place.

  • The Fight-or-Flight Response

    • The fight-or-flight-or-freeze response is regulated by release of adrenaline or noradrenaline.
    • The fight-or-flight response (also called the fight-or-flight-or-freeze response, hyperarousal, or the acute stress response) was first described by Walter Bradford Cannon.
    • Inhibition of stomach and upper-intestinal action to the point where digestion slows down or stops