What is Phase change: Definition and 142 Discussions

In chemistry, thermodynamics, and many other related fields, phase transitions (or phase changes) are the physical processes of transition between the basic states of matter: solid, liquid, and gas, as well as plasma in rare cases.
A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, or others. For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume. The measurement of the external conditions at which the transformation occurs is termed the phase transition. Phase transitions commonly occur in nature and are used today in many technologies.

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  1. D

    Classical Looking for a thermodynamics book that 'ties it all together'

    I am currently a highschool student, and while I've learnt a bit about thermodynamics such as the first and second laws, their implications, I'd like to know how that stuff relates to gases and (without going too deep into it) phase change. Due to the structure of our curriculum, I've learnt...
  2. Precious Adegbite

    I What Is the Smallest Change Detected by a Multiport Interferometer?

    Good morning all... please I'd like to know what's the smallest ever recorded change in phase or wavelength any multiport interferometer has ever been able to detect. And which multiport interferometer detected it.
  3. deepanshu_ch

    I Will Heating a Sealed Container Cause All Liquid to Convert to Vapor?

    Please can one explain what is exactly gonna happen if we have closed container and liquid is present in it and we heat from bottom ? Then whole liquid will converted into vapour or not ? But during the phase change both system in dynamic equilibrium. If both phases are in dynamic equilibrium...
  4. Gwen

    Thermal lattice Boltzmann model ignoring source term -- python code help please

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  5. A

    B Phase Change in Light: A & B Signal Reflections

    I would appreciate knowing if there is any error in the mechanics illustrated in this animation with respect to phase change in the signal reflections shown at A and B, or in the description accompanying it. I have embedded the description with the animation and included it in this post for...
  6. D

    A Heat exchange in a thermal storage based on phase change materials

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  7. L

    Finding equilibrium temperature when there are phase changes

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  8. runningphysics

    Incorrect Calculation of Time for Reactor Energy Phase Change

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  9. Dom Tesilbirth

    The magnetic phase change of an electromagnetic wave during reflection

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  10. bluesteels

    Confusion about whether to use the specific heat of water or ice

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  11. Iwanttolearnphysics

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  12. H

    Understanding Phase Change: R, L & C

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  13. R

    Engineering Spinodal and Isotherms graph on P-V diagram

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  14. N

    Thermodynamics: phase change and latent heat problem

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  15. sneakycooky

    The relationship b/w infrared, temperature, and electron excitation

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  16. Y

    Entropy change when melting ice then refreezing the water

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  17. Y

    Low-Temp Liquid Helium System: Evaporation Heat & Temperature

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  18. F

    How is absorbed thermal energy invested during a phase change?

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  19. T

    Enthelpy vs Internal Energy in Phase Change

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  20. T

    A Which liquids do not supercool?

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  21. Spinnor

    B Phase change or not: oil in the refrigerator

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  22. IshaanM8

    Question about Phase Change & Latent Heat

    Homework Statement When running, some (heat) energy is lost by the evaporation of sweat. If a runner loses 1.0 MJ( Mega Joules) of energy via sweating, calculate an approximate mass of sweat evaporated from the runner. Homework Equations Q = McΔT Q (Joules) = M (Mass) c (Maximum Heat...
  23. DracoMalfoy

    Thermal physics phase change: Liquid copper to solid

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  24. S

    Why does the partial pressure of H2O stay the same

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  25. A

    How to calculate change in pressure from LN2 phase change

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  26. Erickly

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  27. N

    If you threw a warm water balloon into space, would it boil?

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  28. tanaygupta2000

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  29. A

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  30. Marcus95

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  31. Richie Smash

    B Why is the volume of a gas bigger during a phase change

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  32. lavendly

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  33. H

    How water induces phase change of TiO2 after acid-etching?

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  34. M

    Phase of refrigerant crossing heat exchanger devices

    When a refrigerant crosses a heat exchanger device or has some heat added into it, like condenser/evaporator or boiler/cooling tower, does the phase always change? If that's so, why? Or do we need to check if the temperature is above or under the boiling point?
  35. M

    What is a distinct phase change?

    "At pressures above the critical pressure, there is not a distinct phase change process. Instead, the specific volume of the substance continually increases, and at all times there is only one phase present." What does "distinct phase change" mean here? First to understand this I should...
  36. C

    Phase shift of e.m. wave through a glass plate

    Homework Statement Consider a glass plate of refraction index n and thickness ## \Delta x ## placed between a point monochromatic source S and an observer O, as in picture. (a) Prove that, if absorption from the plate is neglegible, then the effect on the wave received by O is the add of a...
  37. V

    I Derivation of phase change parameter in dispersive medium

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  38. Ian Baughman

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  39. D

    Phase Change in a transmission line

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  40. ElPimiento

    Equilibrium temperature of some ice and steam

    Homework Statement "A well-insulated bucket of negligible heat capacity contains 120 g of ice at 0°C. If 20 g of steam at 100°C is injected into the bucket, what is the final equilibrium temperature of the system?" Homework Equations $$Q_{fus} = m_{water}L_{fus}$$ $$Q_{vap} =...
  41. J

    How to calculate time to change the temperature of metal

    So I'm looking to calculate the time required to raise the temperature of a piece of lead. What I know so far: Mass of metal: 4 grams Initial temperature: 250 degrees Celsius Final temperature: 350 degrees Celsius Specific heat of lead: 0.13 kj/kg I'm very new to thermodynamics and don't know if...
  42. Kirmandarren

    Propane phase change in a container

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  43. Ravi Singh choudhary

    What will be the equilibrium state in the liquid N2 chamber?

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  44. Tafe

    Quantity of heat, phase change of ice to water

    Homework Statement A 1x106 kg piece of ice is placed into a lake. How much heat is taken from the lake to raise the temperature of the ice from 0 °C to 1x10-20 °C? How much volume does the lake increase by? Latent heat for water is 334x103 J/kg Homework Equations Found in my textbook, cice =...
  45. Clara Chung

    B Why do water waves not undergo a phase change when they hit a fixed wall?

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  46. S

    Phase change material steady melt temp, like ice water?

    Ice melting in a box has the water coming off it at a temp just above freezing until all the ice is gone. Are all phase change materials pretty much the same, with their immediate containment container exterior staying pretty much just above their phase change temp until all the PCM inside has...
  47. E

    Entropy Change in a Reversible Process multiple phase change

    Homework Statement (a)How much heat must be added to a block of 0.120kg of frozen ammonia initially at 100oC to convert it to a gas at 80oC given the following information? (b) assuming this could be done using a reversible process what would be the total entropy change associated with this...
  48. I

    Simulation of phase change materials

    Dear all, Interested in change phase, I would like to set a simulation to understand the multiphysics phenomena of heat storage in a shell and tube tank between hot water as the heat transfer fluid and a PCM ( phase change material) using the commercial CFD software Fluent. The purpose is to...
  49. I

    Phase change phenomena in Fluent v15

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  50. T

    Grade 11 Thermodynamics Question

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