What is Freezing: Definition and 169 Discussions

Freezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point. In accordance with the internationally established definition, freezing means the solidification phase change of a liquid or the liquid content of a substance, usually due to cooling. Although some authors differentiate solidification from freezing as a process where a liquid turns into a solid by increasing the pressure, the two terms are used interchangeably.
For most substances, the melting and freezing points are the same temperature; however, certain substances possess differing solid–liquid transition temperatures. For example, agar displays a hysteresis in its melting point and freezing point. It melts at 85°C (185°F) and solidifies from 32°C to 40°C (89.6°F to 104°F).

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  1. O

    Freezing time for 1 cm of water

    Hey guys, I have a question... first some backround. I am asking this question is so I can build a backyard skating rink in the fastest way possible. I live in south Jersey so winter is allot of freeze/thaw. The common way for a backyard rink is 1) place a liner 2) fill 2-3 inches 3) let...
  2. K

    Why is the Freezing Point of Pure Water Defined as 0°C?

    Why do we define the freezing point of pure water as 0°C when most pure water does not freeze at that temperature? Instead, it can and does remain in the liquid phase down to temperatures as low as -48°C [Molinaro & Moore, 2011]. Cold-weather clouds throughout the Earth’s atmosphere...
  3. Q

    Boiling and Freezing Points of Solutions

    Homework Statement The aqueous solution with the lowest freezing point of the following group is: 1) 0.01m MgSO4 2) 0.01m NaCl 3) 0.01m CH3CH2OH 4) 0.008m MgCl2 5) all equal Homework Equations Solutions have lower freezing points and higher boiling points than their solvents...
  4. F

    Calculate freezing point depression and boiling point elevation

    Homework Statement Calculate new freezing point and boiling point when 0.47 mol ethylene glycol and 0.14 mol KBr is added to 150g H2O. Express your answer using one decimal place.Homework Equations molality = moles solute/kg solvent ΔTf=i*Kf*m ΔTb=i*Kb*m New bp = ΔTb + normal bp New fp =...
  5. L

    Computer freezing when screensaver comes on

    After about 10 minutes of not moving the mouse or typing, my screensaver comes on, and the colors are kinda messed up and the computer freezes. I tried just disabling the screensaver, but whenever I go to the thing that let's me disable the screensaver, the screensaver comes up on a little...
  6. N

    Strange case: Bottle of water freezing

    Any idea what's going on here: http://www.sootoday.com/content/news/full_story.asp?StoryNumber=50683%20 Thanks...
  7. E

    Freezing Salt Water Experiment

    I'm in a bit of a time crunch for science fair, and there are still a few questions about my experiment that are unanswered. What I'm dong is trying to accelerate the freezing of salt water by adding electrodes to the bottom of my container (attached to a battery). If the ions of the salt are...
  8. P

    Pipe Freezing Time: 150NB Steel Pipe in -15C

    I am trying to ascertain if a 150NB Stainless Steel pipe lagged with 50mm thick insulation would also require to be trace heated. The insulation used is rockwool. The parameters are that the pipe must not freeze solid given 5 straight days of -15 C with static flow. Wind chill is negligible. The...
  9. J

    Entropy of molten lead freezing

    Entropy of molten lead "freezing" Lead melts at 327.5 C.° The latent heat of melting of lead is 24.1 J/g, and the heat capacity of solid lead is 0.14 J/g °C. You take 100 grams of molten lead at a temperature of 327.5 C° and pour it on the sidewalk. The lead freezes and then comes into thermal...
  10. C

    Freezing Lake - Heat Energy Questions

    Homework Statement Freezing Lake A small pond has a layer of ice 1cm thick floating on its surface. The air temperature is -10°C. Steps (a-c) should help you find the final answers in (d) and (e). (a) What is the temperature of the liquid water just below the ice? (b) Write the...
  11. T

    Heat released during freezing of water

    Homework Statement A situation is given whereby a thermometer is placed inside acetone of 80C and is taken out. A layer of ice forms around the surface of the thermometer, does the reading of the thermometer change? Homework Equations - The Attempt at a Solution At first I...
  12. feyn

    Freezing water of different starting temp.

    I have questions to a classic experiment : you have 2 equal containers filled with water. IN one the temperature of the water is 98° Celsius, in the other the water has 25° Celsius. If you put both in the freezer the one with the hotter water freezes first. Now i do understand that one looses...
  13. I

    Finding the freezing point of water at high pressures

    Homework Statement Find the freezing point of water at the bottom of the ocean where the pressure is 32.52bar Homework Equations Clausius-Clapeyron equation in the form of: ln(p2/p1) = deltaHfusion/R * ((1/t2)-(1/t1)) Where the deltaHfusion is 6.008*10^3 J/mol where the...
  14. B

    Freezing point depression in terms of intermolecular forces

    Sorry if this is an obvious question...I understand how the justification via the pressure v temp graph works, but I'm not quite understanding freezing point depression in terms of intermolecular forces and temperature. I was taught that due to attractive IMF between solute and solvent particles...
  15. Gliese123

    ΔTF = KF × b × i freezing point saltwater

    Homework Statement I think this is the right formula: ΔTF = KF × b × i Freezing-point depression. I have the amount of salt added to the water but how am I going to do to calculate the difference in temperature? Or with other words the freezing point of water saturated with salt (NaCl)? Or...
  16. L

    Freezing point depression constant value clarification.

    Hi all, I just need a little clarification here, please. I'm a tutor and I've been helping a student with their freezing point depression lab and the student has to determine the molar mass of an unknown solute from the experimental data provided. I understand the process and have been...
  17. A

    Freezing and Boiling water at the same time

    Hi, As I understand, by placing water in a vacuum and decreasing pressure, vapor pressure will subsequently be increased causing the water to boil. The water will then evaporate, which will cool the water that is left behind. Further evaporation over a period of time will drop the water...
  18. A

    Gradual temperature drop when freezing

    Homework Statement Explain why the temperature gradually drops as the solution is in the process of freezing? Homework Equations None The Attempt at a Solution No idea how to start!
  19. A

    Why Does an LPG Tank Freeze as Gas is Used? Explained

    Hi all, I am having trouble grasping the phenomenon on why the LPG tank freezes as you use up more and more of the gas inside. My understanding is this. Initially, the tank is full of liquefied gas, and as you use up the gas, the pressure inside the tank drops, and since the temperature...
  20. A

    Explanation of Mpemba effect for freezing of water

    I recently came across an odd phenomenon known as Mpemba effect. It says that hot water freezes quicker than cool water provided that temperature difference is not too much. E.g. it can be, say, 30 degrees Celsius and 50 degrees Celsius but not something like 99 and 1. Unfortunately, the book...
  21. F

    HELP water freezing in a tube, expansion principles

    Well, they might be more of a tendency but in a nutshell, I have a water source heat pump unit that we removed and stored. It is now being exposed to freezing temps. Just NOW i realized that I never looked into freezing issues with the coil. I am curious if water has a place to expand, aka...
  22. J

    Colligative Properties, Freezing Point Depression - Chemistry Lab

    Colligative Properties, Freezing Point Depression -- Chemistry Lab Homework Statement In an attempt to hurry the experiment along a student did not completely dissolve the unknown nonelectrolyte. Will the freezing point depression of the solution be larger, unaffected, or smaller compared to...
  23. T

    How does a water droplet freeze on a surface without going into too much detail?

    Is it correct to say that a water droplet on a surface freezes by heat transfer from the droplet through the water-substrate interface, and a subsequent nucleation process whereby minute particles on the surface (or the surface roughness) acts as nucleation centers? Do you know of a...
  24. L

    Can magnetic fields freeze charged particles?

    this is just a naive question from a person who is not a physican, imagine that charged particles ( ions ) could only move in a plane. if a homogeneous magnetic field perpendicular is imposed what would happen ? i think that the particles must come to rest since they emitt electromagnetic...
  25. Jadaav

    Impurities Impact Melting & Freezing: Explained

    "For a pure substance, melting occurs at the same temperature as freezing." Does it means that if impurities are added, then the melting point of the substance is not at the same temperature as freezing ? If yes, how you would explain this ?
  26. J

    Relationship between turbulence and freezing?

    How fast do i need to pump water in a 10" aluminum pipe to prevent freezing? Assume 32*F inlet temp and 0*F ambient . For my conditions, the temps will vary and T ambient easily gets down to -20*F or more.
  27. U

    Freezing time for 1mL of water

    Hi, Does anyone have a formula for the freezing time (ie time taken for it to freeze) of a fixed volume of water (1mL) at a given temperature (Ts) and pressure (1 Atmosphere) when the surrounding temperature is set to below 0 Celsius (Ta < 0C) ? ie. I'm looking for Time to freeze if you...
  28. M

    Freezing Liquid with Compressed Nitrogen - Is it Possible?

    Is it possible to freeze liquid in tank with compressed nitrogen? Tank has double sides where nitrogen is relased. Also there are numerous nozzles inside tank through which nitrogen spray. Would be final result solid form of liquid? What is difference in time, amount of nitrogen needed for 50...
  29. C

    Chemistry - Change of freezing point

    Homework Statement The enthalpy of fusion of mercury is 2.292kJ/mol and its normal freezing point s 234.3K with a change in molar volume of +0.517cm^3 /mol on melting. At what temperature will the bottom of a column of mercury (density 13.6 g/cm^3) of height 10.0m be expected to freeze...
  30. J

    New computer constantly freezing?

    New computer constantly freezing?? Hey guys, I have a problem here. I recently bought a brand new computer with Windows 7 Home Premium on it. It has an AMD Athlon dual core 2.0 ghz processor, and the computer initially came with 2 gigs of DDR-2 RAM. Now, when I got the computer, I threw in...
  31. S

    Freezing potential of Quintessence

    Dear all, I am reading some texts about quintessence. As you one of the best textbooks for cosmology is Weinberg's. in page 90 of his book he states that if we consider astronomical units we can see that a good quintessence potential is V(\phi)= (M^(4+alpha)) * phi ^(-alpha) and M has...
  32. L

    Computer has intermittent freezing problems

    When I first turn on my computer in the morning, it will have intermittent freezing problems when I'm trying to do stuff. Like if I come here and click on something, it will freeze for a few seconds, but my cursor can still move, but it's just slow. After everything I do, it will stop, take a...
  33. T

    Can a Wine with 28.4% Ethanol by Weight Freeze at -10 C?

    Homework Statement Wine that is 28.4% ethanol by wt is set outside. Will it freeze if the temp drops to -10 C? (assume water is the solvent) Homework Equations \DeltaTfp = kfp*molality of solute The Attempt at a Solution 2.84 g of ethanol/10 g total =.284 mole \DeltaTfp= -10 ?
  34. Math Is Hard

    Medical Fat Freezing: A New Way to Shed Body Fat?

    I couldn't sleep last night and was watching some news special at 2 AM on "fat freezing", a new way to shed body fat. http://abcnews.go.com/Health/freezing-fat-fda-green-lights-weight-loss-treatment/story?id=11641994 I don't know if this is the same video, but it was wild! They took this...
  35. Andrew Mason

    Connection between Freezing Europe and the BP spill

    The unusually cold weather in Europe must be related to the gulf stream which gives Europe its normally balmy temperatures as far north as the Arctic Circle in Norway. It was noticed this summer that the gulf stream had slowed down to almost a stop. Some scientists attributed this to the BP...
  36. T

    Thermodynamics: Freezing Point Depression

    Homework Statement 200 g of ethylene glycol (HOCH2CH2OH) is dissolved in 1.00 L of water at 25°C. The cryoscopic constant of water is 1.86 °C molal-1. If the solution is chilled to -25°C, how much ice (in g) will be separated out? Homework Equations ΔT=Kfm, where Kf is and cryoscopic...
  37. I

    Air temperature & water freezing

    Could somebody please estimate the air temperature that water freezes at. During a recent very cold night I left an open plastic container of ~50ml of water next to an alcohol thermometer in an uninsulated garden shed. By morning the thermometer was reading minus 3 degrees Celcius but the...
  38. T

    37.8g of water to give a freezing point of -.15 degrees C

    Hey, I really need help in my chem homework. :( how many grams of ethyl alcohol CH2OHCH2OH must be added to 37.8g of water to give a freezing point of -.15 degrees C.
  39. G

    Freezing Point Depression Equation in Calculus Notation?

    Homework Statement How do I write it in calculus notation? Delta T = i k m were Delta T = Change of temperature i = van't Hoff value m = concentration in molality k = molal freezing/boiling point constant for the solvent THANKS! Homework Equations The Attempt at a Solution
  40. A

    Water vapor condensation and freezing

    [b]1. When water vapor is condensing or liquid water is freezing? Homework Equations [b]3. The two are affected by the energy of the sorrounding environment is being absorbed into the water.
  41. J

    Hypothetical spherical ball freezing.

    I've been pondering this question a while regarding how water freezes. Assuming the temperature above a lake is 0 degrees centigrade, the water at the top of the lake would decrease in temperature until 4 degrees centigrade at which point, being at its densest, would sink towards the bottom of...
  42. J

    Relative temperatures during freezing of Water

    Hi I was wondering if anyone could help me out with this question? You place 100ml of water into a freezer and monitor the variation of the temperature of the water with time. After some time you find that the temperature reaches 0ºC, then remains constant at 0ºC for a period of time before...
  43. A

    Batteries at freezing temperatures

    I am trying to develop a battery operated invention that will be used primarily in sub freezing conditions. From what I can tell from my research so far, a simple 9 volt NiMH or lithium will work fine under these conditions. The only problem I foresee though is that when this was eventually a...
  44. U

    Calculating Freezing Point of K2CrO4 Solution

    Homework Statement A solution is made by dissolving 250.0 g of solid potassium chromate (K2CrO4) in 1.00 kg of water? what will be the freezing point of the new solution. Homework Equations [Delta]T(freezing point)=(Van't Hoff Factor)(molal concentration of solute particles)(molal...
  45. M

    Freezing in the gulf oil pipeline

    I was wondering if someone could explain how ice crystals are being formed in the tank/pipeline BP is trying to use to stem the flood of oil pumping into the ocean. A friend and me were discussing it and a few questions came to mind about it, not just related to this issue. He suggested that...
  46. Z

    Electrolytes nd freezing point. on mobile, pardon my typing.

    in chem. class asked the question nd he ignored me, i hope smeone here can help me? wht are the properties of electrolytes nd how do yu kno they coduct electcity nd also how ud yu determinet lowest freezing eezing poin
  47. B

    Strange behavior of the density of the water around the freezing point

    please is there a topic that discuss with illustration factor that causes Strange behavior of the density of the water around the freezing point
  48. M

    What mass of the ethanol is she freezing?

    A technician freezes some ethanol by removing 9.53x10^4 J of heat energy from it at its melting point. What mass of the ethanol is she freezing?
  49. F

    Freezing point of flowing water.

    Hello, this is my first post :) I will be very glad if you would answer my question. Does freezing point decrease if water is flowing or in otjer words,"does flowing water freeze more easily than still water". if the answer is yes, would you please give me the link of the source or paper. iwill...
  50. K

    Determining molar mass by freezing point depression lab

    Im doing my chemistry lab and ran into trouble with this problem. I am not even where to start or what formulas to use. Any ideas? Thanks. Suppose that a student calculated Kf of biphenyl to be 81.2 C kg/mol. Calculate the molar mass of an unknown if a solution containing 1.64g of an...
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