Freezing point depression

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	Melting point - Wikipedia, the free encyclopedia
		For example, the melting point and freezing point of the element mercury is 234.32 kelvins (−38.83 °C or −37.89 °F).
		Water's Melting/Freezing point is 0 C, or 32 F.
		Unlike the boiling point, the melting point is relatively insensitive to pressure.
	en.wikipedia.org /wiki/Freezing_point (257 words)

	CHEM 1112/MWFPDEP/Stone
		In this experiment you will determine the molecular weight of an unknown substance by measuring the freezing point depression of an aqueous solution of the unknown.
		To determine the molecular weight of an unknown organic compound by measuring the freezing point depression of an aqueous solution of the compound.
		At the freezing point the temperature remains constant because as the liquid solidifies, heat equal to the enthalpy of fusion is released.
	wwwchem.csustan.edu /chem1112/mwfpdep.htm (1067 words)

	General Chemistry Online: Glossary:
		The freezing point depression is roughly proportional to the molality
		Freezing point depression is an example of a colligative property
		The freezing point of a solution is always lower than the freezing point of the pure solvent.
	antoine.frostburg.edu /chem/senese/101/glossary/f.shtml (718 words)

	Freezing Point Depresssion Lab
		Cooling the solution below the freezing point of the solvent restores the dynamic equilibrium because it both reduces the number of molecules that have enough kinetic energy to break free from the solid and become liquid again and it increases the number of molecules in the liquid with low enough kinetic energy to become solid.
		The actual value of the van't Hoff factor i, or number of dissolved particles per formula unit, is determined from the measured freezing point.
		Freezing, like any phase change, is an equilibrium process; that is, the rate at which particles leave the liquid state and become solid is the same as the rate at which particles leave the solid state and become liquid.
	chemweb.calpoly.edu /chem/125/125LabExp/FPDepression (590 words)

	Freezing-point depression - Wikipedia, the free encyclopedia
		Freezing point depression can be used to measure the degree of dissociation of a solute or to measure its activity.
		Freezing-point depression is the difference between the freezing points of a pure solvent and a solution mixed with a solute.
		for water is 1.858 K·kg/mol which means that per mole of solute dissolved in a kilogram of water the freezing point depression is 1.858 kelvins.
	en.wikipedia.org /wiki/Freezing-point_depression (228 words)

	Freezing Point Depression
		Freezing point depression is not just another way of referring to the early February blues.
		In general, for dilute solutions, the amount of change in the freezing point is proportional to the concentration of the solute in the solution.
		For example, consider the effect that salt has on the melting point of ice (which is the same as the freezing point of water).
	dl.clackamas.cc.or.us /ch105-03/freezing.htm (201 words)

	MCTC Freezing Point Depression for Lauric Acid
		is the freezing point depression constant (characteristic of the solvent) and m is the molality of the solution in moles of solute particles per kilogram of solvent (moles/kg).
		Freezing point depression occurs when a solute is added to a solvent producing a solution having lower freezing point temperature than the pure solvent.
		One way to understand the freezing point depression effect is to consider the solute particles as interfering or standing between the solvent particles.
	www.mctc.mnscu.edu /chemistry/resources/C1152/laboratory/Freezing%20Point%20Depression.htm (1247 words)

	Freezing Point Depression and Bo
		Freezing Point Depression and Bo Molal Freezing Point Depression and Boiling Point Elevation
	jesuitnola.org /upload/clark/Refs/FP_BP_molal.htm (13 words)

	Freezing point depression
		The depression of the freezing point of a solution with respect to the pure solvent is analogous to boiling point elevation.
		Thus, at the freezing point of a solution, the solvent in the solution and the solvent in the solid (which is composed only of solvent) must coexist.
		Thus, freezing point corresponds to the point where the solution vapor pressure curve intersects that of the pure solid solvent.
	www.nyu.edu /classes/tuckerman/honors.chem/lectures/lecture_13/node8.html (251 words)

	freeze.doc
		Two common examples of solvent properties that are altered are depression of the freezing point and elevation of the boiling point.
		Purpose: The purpose of this laboratory activity is to determine the molecular weight of urea using the technique of freezing point depression.
		Using the change in freezing point, the kilograms of water used, and the freezing point constant for water, calculate the number of moles of urea used in each trial.
	services.juniata.edu /ScienceInMotion/chem/labs/ap/freeze.doc (749 words)

	Notes for Lab 1
		Since there is experimental scatter in the temperature measurements, you will have to use a graphing technique to determine exactly what the freezing point is (Remember the temperature work in Chem 31 lab with Mg and MgO?).
		Freezing is an exothermic process, so the temperature should stop dropping, and level off until the sample is completely frozen.
		Since the freezing stearic acid is hard to see, the way you determine when it solidifies is to measure the temperature at regular intervals.
	www.uvm.edu /~mcalichm/32Notes1.html (545 words)

	freezing point, depression of
		Measurement of freezing-point depression is a useful method of determining the molecular weights of solutes.
		Lowering of a solution's freezing point below that of the pure solvent&; it depends on the number of molecules of solute dissolved in it.
		The depression d produced by the presence of a solute of molar concentration C is given by the equation d = KC, where K is a constant (called the cryoscopic constant) for the solvent concerned.
	www.tiscali.co.uk /reference/encyclopaedia/hutchinson/m0020493.html (179 words)

	Freezing point depression
		is the molal freezing point depression constant of the solvent and m is the molal concentration of the solute.
		This freezing point depression is an example of a colligative property, one which depends only on the number of moles of the solute.
		C, the freezing point of the mixture is 5.5 - 2.45 = 3.0
	www.cartage.org.lb /en/themes/Sciences/Chemistry/Generalchemistry/Solutions/Solubility/Solutionsindex/Colligative/Freezing/Freezing.htm (340 words)

	Molar Mass Determination from F.P. Depression
		The freezing point depression constant, Kf, for 1,4- dichlorobenzene is 7.10C/m.
		The freezing point of a solvent depends upon the concentration of the dissolved solute and the nature of the solvent.
		The freezing point of 1, 4-dichlorobenzene is 53C.
	www.chem.vt.edu /RVGS/ACT/lab/Experiments/Exp_8-Molar_Mass.html (555 words)

	Using Freezing-Point Depression
		This property, known as freezing-point depression, is a colligative property; that is, it depends on the ratio of solute and solvent particles, not on the nature of the substance itself.
		By measuring the freezing point depression, T, and the mass of benzoic acid, you can use the formula above to find the molecular weight of the benzoic acid solute, in g/mol.
		To determine the freezing point of the benzoic acid-lauric acid solution, you need to determine the temperature at which the mixture initially started to freeze.
	www.accd.edu /nvc/areas/chem/ComDALab/Lab15/15FPDepr.htm (1207 words)

	Freezing Point Depression & Molecular Weight
		The purpose of this activity is to determine the molecular weight of an unknown substance by measuring the freezing point depression produced in a known solvent.
		The freezing point depression constant for this substance is k = -6.94 C°/m.
		Measure the mass and melting point of naphthalene.
	www.dbooth.net /mhs/ap/apcolligative.html (218 words)

	Dorlands Medical Dictionary
		depression of normal electrical rhythms recorded from the cerebral cortex, spreading outward from an area of stimulation or cortical damage; the rate of spread closely approximates the visual aura of a migraine.
		However, this term is commonly used in a broader sense to cover all severe depressions causing gross impairment of social or occupational functioning, i.e., as a rough equivalent of major depressive disorder or of endogenous depression.
		a depression that is precipitated by a stressful life event or other environmental factor, in contrast to an endogenous depression, with an absence of significant vegetative disturbances; see also neurotic d.
	www.mercksource.com /pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_d_10zPzhtm (4148 words)

	Freezing-Point Depression
		: the lowering of the freezing point of a liquid by addition of a solute.
	www.chem.purdue.edu /gchelp/gloss/freezedep.html (15 words)

	Che135L < Molar Mass by Freezing Point Depression
		The freezing point of the solvent (the temperature at which solid and liquid phases are in equilibrium) is determined by cooling the solution and plotting a graph of temperature as a function of time.
		In practice, it is necessary to first determine the freezing point of the solvent alone, since the solvent may not be pure.
		However, a solution will freeze over a range of temperatures and will not exhibit the constant freezing point of the pure liquid; instead of exhibiting a horizontal portion, the plot will show a change of slope when solid solvent begins to form.
	web.centre.edu /miles/che135labs/Colligative%20properties.htm (1451 words)

	Freezing Point Depression
		is the molal freezing point depression constant, which has a characteristic value for a given solvent.
		The freezing point of a solution is lower than the freezing point of the pure solvent.
		is the freezing point of the pure solvent.
	www.chem.latech.edu /%7Ededdy/chem104/Integrated%20104_Freezing.htm (151 words)

	Molecular Weigh from Freezing Point Depression Data
		The molal freezing point depression constant of benzene is 5.12
		Calculation of Molecular Weight from Freezing Point Depression Data
		The freezing point of a solution that contains 1.00 g of an unknown compound, (A), dissolved in 10.0 g of benzene is found to be 2.07
	chemed.chem.purdue.edu /genchem/probsolv/colligative/fpmw1.2.html (111 words)

	Freezing Point Depression
		Note on phase diagram that the freezing point decreases and the boiling point increases for a solution, as a result of the lowering of the vapor pressure.
	www.public.asu.edu /~jpbirk/CHM-113_BLB/Chpt13/sld030.htm (27 words)

	The MSDS HyperGlossary: Freezing Point
		The normal freezing point is the temperature at a substance melts (or freezes) at one atmosphere (760 torr = 760 mm Hg = 14.7 psi = 101.3 kPa) of pressure.
		Freezing point is the temperature at which a liquid becomes a solid at normal atmospheric pressure.
		A more specific definition of freezing point is the temperature at which solid and liquid phases coexist in equilibrium.
	www.ilpi.com /msds/ref/freezingpoint.html (323 words)

	Freezing Point Depression and Vapor Pressure Lowering
		So, I contend that BOTH the equilibrium freezing point and vapor pressure of a liquid are decreased upon addition of a non-volatile, liquid-soluble/solid-insoluble solute to the liquid phase.
		The freezing point of the solid + solution is less than the freezing point of the pure solid.
		Of course, Tfp would be correct, and Tbp would be incorrect to the question of "Which one is lowered?" With this being said, the AP Chem tests two answers do not make sense since BOTH the vapor pressure and the freezing point will be decreased.
	www.newton.dep.anl.gov /askasci/chem00/chem00700.htm (1027 words)

	FREEZING POINT DEPRESSION
		The vapor pressure is lowered, the boiling point is raised, and the freezing point is lowered.
		For dilute solutions, the decrease in freezing point and the increase in boiling point are directly proportional to the number of moles of solute particles dissolved per 1000 grams of solvent (molality).
		Both the freezing of the ice cream and the decrease in temperature of the snow-salt mixtures represent a loss of heat.
	www.oswego.edu /wscp/fp.htm (872 words)

	General Chemistry Online: FAQ: Solutions: Why does salt melt ice?
		The higher the concentration of salt, the greater the freezing point depression [1].
		It is important to realize that freezing point depression occurs because the concentration of water molecules in a solution is less than the concentration in pure water.
		The hypothesis that solutes with large molecules cause a larger freezing point depression than those with smaller molecules is not in accord with experimental data!
	antoine.frostburg.edu /chem/senese/101/solutions/faq/why-salt-melts-ice.shtml (801 words)

	AllRefer.com - glycoprotein (Biochemistry) - Encyclopedia
		Among other glycoproteins, one particularly interesting example is isolated from certain antarctic fishes who survive near-freezing water temperatures as a result of freezing-point depression of their blood serum by a globular glycoprotein.
		This molecule is a remarkably effective freezing point depressant.
		Solutions of glycoproteins usually exhibit high viscosity, an observation explaining the highly viscous character of egg white, which is composed largely of the glycoprotein ovalbumin.
	reference.allrefer.com /encyclopedia/G/glycopro.html (348 words)

	General Chemistry Online: FAQ: Solutions: How can freezing point depression be explained in terms of free energies?
		Appendix: Derivation of the freezing point depression equation
		That would suggest that equal concentrations of ions or molecules cause equal freezing point depressions, regardless of what the solute is. Experimental results agree with this prediction, so long as the concentrations are low.
		The lower chemical potential of solution water shifts the point of intersection to the left, so the freezing point of the solution is lower than the freezing point of the pure solvent.
	antoine.frostburg.edu /chem/senese/101/solutions/faq/thermo-explanation-of-freezingpoint-depression.shtml (888 words)

	Making Ice Cream by Freezing Point Depression
		You must lower the freezing point of the ice by adding rock salt to the ice cubes or your ice cream mixture will not freeze.
		Background Material: Sugar in ice cream lowers the freezing point of the ice cream mixture and therefore decreases the possibility that ice crystals will form.
		In order to freeze the ice cream mixture, ice cubes are not enough.
	www.realscience.breckschool.org /upper/fruen/files/Experiments/files/4.8IceCreamFPDep.html (218 words)

	102 Exp 3
		The colligative property of freezing point depression is akin to that of boiling point elevation.
		Using the measured freezing points, the molecular weight of the unknown may then be determined by rearranging the following expression for the freezing point depression:
		The freezing point constant for cyclohexane is 20
	capital2.capital.edu /faculty/wbecktel/102L3.html (953 words)

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