What is Liquids: Definition and 198 Discussions

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena. Water is, by far, the most common liquid on Earth.
The density of a liquid is usually close to that of a solid, and much higher than in a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids. Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is in gaseous form (with traces of detectable solid matter) as interstellar clouds or in plasma from within stars.

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  1. H

    The effects of absolute zero temperature

    I can visualize gas molecules, contained in a vessel, randomly bouncing into each other. As temperature increases, the collisions occur more rapidly. I suppose this also applies to liquids. I'll guess that a liquid's boiling point is where the molecular collisions become so violent that...
  2. J

    A Can the Magnetocaloric effect be used for heating liquids?

    There's a recent article about cooling hydrogen in an industrial scale with the magnetocaloric effect. Read the article here But where does the heat go there? Can it be used for heating liquids? Could it be used for an ecologically and economically viable source of energy like a heat pump...
  3. maryelin

    How to get the density equation using the Reidel Equation for vapor liquids?

    I need to know how to get the density equation using the Reidel Equation for vapor liquids... how is the calculations to get
  4. T

    I Temperature change due to mixing liquids, heating and heat losses

    Hello, I am stuck how to proceed with the equations below. The problem: A tank containing ##m_0## mass, with a temperature of ##T_0##, is to be filled with a total mass of ##m_1##, with the constant mass flow rate ##G## and temperature ##T_1## during ##t_p## seconds. ##T_0>T_1##. Other than the...
  5. G

    Manometer containing two liquids

    Figure: $$p_A^r=-0,11\, \textrm{at}\rightarrow p_A=90534\, \textrm{Pa}$$ $$\rho_A^r=1,6\rightarrow \rho_A=\rho_{AR}\cdot \rho_{H2O}=1600\, \textrm{kg}/\textrm{m}^3$$ $$\rho_1=1,225\, \textrm{kg}/\textrm{m}^3$$ $$\left. \begin{array}{l} \textrm{LOOP I}\rightarrow p_A-p_1=-\rho_A (Z_A-Z_1) \\...
  6. MRG1373

    Diffusion coefficient of gases in liquids

    recently I'm looking for diffusion coefficient of gases in liquids. I have read "THE PROPERTIES OF GASES AND LIQUIDS" from Bruce E. Poling. but in this book it isn't directly mention what is diffusion coefficient of gases in liquids. can we using liquid-liquid models for gas-liquid models?
  7. luciriv

    Two immiscible liquids in a container

    I really need a help with this exercise: A ##1.75##-m-high container has two immiscible liquids stacked on top of each other. The upper liquid has specific gravity ##SG = 0.45## and the other has density ##\rho = 61.78\, lbf/ft^3##. If the pressure exerted by the lower liquid at the bottom is...
  8. hagopbul

    Freezing temperature of vaccines

    Hello all: I have this question , as we all watch the vaccine of Covid-19 reach the market I had this question if the storage temperature of this vaccine is between -20 c to -70c Why the nano droplets in this liquid do not create ice the liquid is not freezing under that conditions although it...
  9. J

    Does DNA get affected by the concentration of the liquids around it?

    Hi I would just like to know if DNA is affected by the concentration of liquids around it. Thanks and best regards,
  10. S

    Pressure at the bottom of a cube immersed in two liquids

    I am not sure about value of depth I need to use. What I did: Hydrostatic pressure at bottom of cube = hydrostatic pressure by oil + hydrostatic pressure by water = ρoil . g . d + ρwater . g . h Is it correct I use value d = 0.2 m for depth of oil and value of h = 0.02 m for depth of water to...
  11. brotherbobby

    Pressures in a U Tube along a line - different liquids

    Yes, pressure is same along the line for both the tubes since the liquids are in equlibrium. (I ignore the slightly longer air column in the left compared to the right). Is my answer correct?
  12. G

    Thermodynamic properties of compressed liquids

    Hi All, I have review my thermodynamic notes (~35 year ago..), and I could not able to restore how to get thermodynamic properties (u,h,s,v ..) for compressed liquids. I have found properties tables for compressed liquids ( for water..) but unfortunately the data starts at 5MPa. What if I look...
  13. brotherbobby

    Pressure due to two liquids in a U-tube

    (a) Situation (2) is my answer (which cannot be in static equilibrium). The pressures in the lower dashed line (##P_2##) has to be the same on either side (for equilibrium). That means the pressure due to the red liquid is equal to the pressure due to the same length of air column (length)...
  14. Adesh

    Chemistry Why do we say that the concentration of solids and liquids are constant?

    I was introduced to the concepts like molarity, molality , mole fraction, formality, normality etc. during general chemistry and it was said that these concepts are used to measure the concentration of solutions. But as the thing called Chemical Equilibrium came I was surprised when I read "In...
  15. L

    A Non-equilibrium Statistical Mechanics of Liquids

    Molecular Transport equations for Liquids are harder to compute than that for gases, because intermolecular interactions are far more important in liquids. A System of equations for particle Distribution function and the correlation functions (BBGKY-Hierarchy) is used in General. For gases, it...
  16. L

    A Why do we study quantum spin liquids?

    What kind of research is currently going on in the field of quantum spin liquids and why do we study spin liquids?
  17. N

    Blocks Floating in Liquids

    Since they're all in the same liquid I'm assuming the buoyant forces would be the same on each block. But then I think about the volumes of the blocks, and them being different. I'm not sure if the block's volume would affect the buoyant force. Any help would be great, thanks!
  18. K

    Thermal Expansion in Liquids and Steel

    This is a repost as I didn't read the community guidelines the first time. Hopefully this is better! First thing I did was write down both the linear and volume expansion formulas. I then multiplied my alpha by 3 and used the volume expansion equation for both materials. ∆V oil > ∆V pot, at the...
  19. T

    A Do any liquids NOT supercool?

    It seems like having the ability to become supercooled below their melting point is the default for liquids (at least liquids without suspended particles, without many interfaces, and without other perturbations). Are there any liquids that don't supercool at all? Or if not, are there any...
  20. S

    Q&A: How Does Work & Energy Relate to Solids, Liquids & Gases?

    I can understand how this applies to gases as in that scenario work done = pressure * change in volume and if change in volume is zero then W=0 so change in internal energy = Q. But I do not understand how this applies generally to all types of substances, say solid, liquid and gas.
  21. J

    Finding heat capacity for liquids

    liquid melting point (degrees C) boiling point (degrees C) water (H2O) 0 100 sodium (Na) 98 883 Sodium-potassium(NaK) -11 785 Lead(Pb) 327 1749 I'm prettttty sure by consulting the literature means by using the above table… but if that's the case then how in the world do you find Cv...
  22. A

    B Why is the height of a liquid not affected by the radius of a U-Shaped tube

    Why the height of liquid is not affected by the radius of U-Shaped tube . ..my textbook says this and it does make sense because if increase the radius of u shaped tube the height of liquid should decrease as the liquids take shape of their container. Edit : I could not make the title longer...
  23. A

    B What easily avaible liquids are transparent in IR?

    Hi I want to make a infrared nonimaging concentrator, but since crystals needed for lenses are difficult to work with for an amateur, want to use liquids. I am interested in the 1-12 micron spectrum; what liquids could i use?
  24. Akash47

    Finding the density of a block in two layers of liquids

    Homework Statement A layer of liquid with density ##800~kg/m^3## floats on top of a volume of water. A block floats at the oil-water interface with ##3/4## of it in water and the rest of it in the liquid. What is the density of the block? Homework Equations Buoyancy =##vρg## where ##v##=...
  25. Akash47

    Pressure at the bottom of a container containing two liquids

    Homework Statement (In the attachment)There is two layers of liquids in the container .The density of the upper layer of the container, ##ρ_1=800kg/m^3## and the density of the bottom layer of the container ,##ρ_2=13600kg/m^3## .What is the pressure at the bottom of the container? Homework...
  26. P

    Speed of sound: viscosity dependece in liquids and solids

    Hello, Wikipedia gave me prior hints as to how the speed of sound depends on viscosity but after searching on Google scholar and Google, I have yet to find any direct equations/findings that give a direct relationship of the speed of sound to the visocisty of fluids and solids outside of...
  27. Muhammad Danish

    Pressure in Liquids: How Does It Affect Volume?

    Homework Statement Homework Equations How does atmospheric pressure affects the volume of liquid? What will be the volume of the air bubble at the bottom of the lake? The Attempt at a Solution At the surface, the volume is 6.0cm3. So at the bottom, more pressure will be exerted so it will be...
  28. cpxuvs

    Fill a small bottle with layered liquids

    Fill a small bottle with layered liquids, such as water and oil. This bottle will move slowly and irregularly in horizontal direction. What will happen to the stratified surface due to inertia? Is there any way to keep this stratified surface horizontal all the time?If possible, I hope that the...
  29. dRic2

    Viscosity and thermal diffusivity in liquids and gases

    Hi PF, I was wondering about this for some time and I can get my head around it. Viscosity ##\mu## is a "measure" of the momentum flux Thermal diffusivity ##\alpha## is a "measure" of the heat flux (kinetic energy of molecules) In gases both viscous stresses and heat flux take place due to...
  30. YNesterov

    How to find m1 in T = ( m1c1T1 + m2c2T2 ) / ( m1c1 + m2c2 )

    Homework Statement How to find mass of one of the two liquids being mixed if we know all other variables in this formula T = ( m1c1T1 + m2c2T2 ) / ( m1c1 + m2c2 ) ? Homework Equations T = ( m1c1T1 + m2c2T2 ) / ( m1c1 + m2c2 ) The Attempt at a Solution
  31. S

    What cuvette to use for fast vaporizing liquids?

    What type of cuvettes are you using for fast vaporizing liquids at room temperature ? I found that cuvettes with Teflon stoppers are working so far but the problem is that at room temperature stopper to cuvette wall seal is not enough to hold that pressure so above 15degrees C vapours are...
  32. M

    Can a fish swim in incredibly viscous-dominated liquids?

    I was wondering, can a fish swim in incredibly viscous-dominated liquids? I'm thinking it cannot. My first thought is to consider the Navier-Stokes equations and see that the inertial and transient terms are small, so flow is not accelerating, and thus the fish couldn't accelerate either. Any...
  33. L

    Liquids: Pascal's Principle and fluid collisions

    Take a U-shaped piece of pipe, standing upwards. Fill the bottom part with liquid and leave the 'prongs' open. Now slam a parcel of liquid into one end at high speed. The other end will experience some momentum exchange and go pushed upwards. Now take the same test case and add some piping...
  34. kolleamm

    Do liquids absorb sound better than solids?

    I'm brainstorming ideas on how I could possibly create a sound proof box to block out the noise from my servo. I was thinking to create a plastic box with hollow walls that could be filled with some sort of liquid, not water, but maybe something with low viscosity to absorb the sound. Would...
  35. A

    Measuring contact angle of immiscible liquids

    I am looking for sources which describe how to measure the contact angle between immiscible liquids in a tube. The literature seems to be extremely lacking so if anyone has any knowledge I would appreciate the help.
  36. A

    A Contact Angle of Immiscible Liquids in a Tube

    I'm having trouble finding any sources which describe how to accurately measure the contact angle between immiscible liquids in a tube. Any help would be appreciated.
  37. S

    A solid cylinder of uniform density of 0.85 g/cm3 floats in

    Homework Statement A solid cylinder of uniform density of 0.85 g/cm3 floats in a glass of water tinted light blue by food coloring. https://s1.lite.msu.edu/res/msu/kashy/physicsLib02/32_Fluids1_Pascal_Arch/graphics/archimedes.gif Its circular surfaces are horizontal. What effect will the...
  38. G

    High-pressure compression of liquids

    Hello, My memories of fluid mechanics are very rusty and therefore I was wondering if you could help me with this hypothetical problem. Let's say I want to generate very high hydrostatic pressures in a liquid (of order of 400 kbar). Would it be enough to do the following: take a rod weighting 1...
  39. Jaime ortega

    I Bubbles travelling through viscous liquids

    Hi, Im doing a Invesitgation of bubbles traveling through liquids. I am blowing bubbles of fixed volume up different viscous liquids. I seem to have got a anomaly but I can't explain it When recording one of the repeats in the foam bath I saw that the bubble rushed up the liquid. It took 1.4...
  40. A

    A Plank Radiation Spectrum Liquids Wavelength VS Temp

    Hello, Are there any Plank Radiation Spectrums for liquids? What I really want to know is, for a given liquid, what wavelength of light is emitted for a given temperature. For example, if I journey to the center of the Earth, the molten lava is about a thousand degrees, hot enough to emit red...
  41. UMath1

    Solids and Liquids in Kinetics and Equilibrium

    I just now read in my textbook that solids and liquids are not included in equilibrium expressions, are they included in rate laws? If not, why? Would a greater molar amount of solid or liquid increase the rate of reaction? And why isn't surface area included in Rate Laws? Also, for the...
  42. P

    Why does 'breaking' not occur in liquids and gases?

    I'm not exactly sure whether this qualifies as quantum mechanics, but it has to do with how atoms work: suppose a glass plate falls and breaks (into two pieces, let's say, to keep things simple) on the floor. Is it possible to put it back together so that there is no longer a crack between the...
  43. O

    Why do balls of different sizes fall at different speeds in oil?

    Hi, it's my first post. When a golf ball and a bowling ball get dropped from the same height. They will both hit the same hit the ground at the same time. But when you drop a ball with radius R and another ball eith radius 2R inside a cylinder with oil then the ball with the biggest radius...
  44. R

    Mixing two different liquids at different temperatures

    When I pour two different liquids at different temperatures, into the same container, the temperature will be uneven at the start but then will approach equilibrium. Similarly, the concentrations of each liquid will be uneven but when mixing is complete, there will be the same concentrations...
  45. Dlhill13

    Liquids and Electricity

    Hello everyone, I am currently working on a project to design a more efficient method of electricity production in the nuclear industry. I haven't been able to find anything online (and chemistry isn't exactly my strong suit most of the time), but I wanted to know if anyone knows of a liquid or...
  46. F

    Fluid Dynamics: Static pressure in compressible Liquids

    Homework Statement [/B] "Derive a relation between the static pressure P at a point and its depth y from the free surface of the liquid. Given the surface density of liquid is ρο, and compressibility of the liquid is k." Homework Equations ##ρ(P) = ρ_οe^{kP}## ##dP = ρg dy## The Attempt at a...
  47. Rodwen

    Light absorbtion and change in temperature of liquids

    Hi hi, Sorry if this is awful and boring. Basically what I want to work out is a way to differentiate two different liquids by touch (specifically, temperature) after shining a light on them. A thermometer cannot be used. The variables open here are the compositions of the liquid (I'm going...
  48. A

    Interpreting Kinetic Temperature for Solids / Liquids

    Hi all, I'm brushing up on some thermodynamics, and having been reading up on the interpretation of temperature as derived from kinetic theory. I can follow the derivation for an ideal, monatomic gas which relates temperature to the average, translational kinetic energy of the molecules. Most...