Questions tagged [phase-diagram]

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How can it be justified that the phase difference between voltage and current for inductor is $\pi/2?$

The inductor is an ideal one, the phase difference is with respect to current, and the voltage varies by the law $V=V_Lsin(\omega t).$ One can prove that the current function will come out to be $I=...
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Chemical potential interpretation for QCD phase diagram

I'm studying the QDC phase diagram at finite densities and I'm having some trouble understanding the role of the chemical potential. It's clear how, if I increase the density of particles at $T=0$, I ...
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Vaporization - phase diagram

I understand what boiling and vaporization is. But what puzzles me is the phase diagram. When I spill a glass of water in my room, it will soon vaporize, though there was normal atmospheric pressure ...
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Water boiling point at room temperature (30 C) and thermodynamic tables

We all know that water boils at $1\rm\,atm$ at $100°\rm\, C$. But if we maintain the water temperature at $30°\rm\, C$ and instead let the pressure drop (in a vacuum chamber) to around $0.3\rm\, bar$, ...
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What happens to water as it is increasingly compressed?

Imagine we put some volume of water in an infinitely strong container, and then start to slowly exert a force on the top of the water , with increasing pressure. What happens to the water over time? ...
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How can a system experience spinodal decomposition?

If we have a thermodynamic system with a binode and spinode, when is it possible to cross the metastable state without perturbation so that my system experiences spinodal decomposition? My suggestions ...
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Why is the subscript $f$ used to refer to properties relating to that of saturated liquid?

In the formula for calculating Vapour Quality, the properties relating to the saturated liquid have a subscript $f$. The properties relating to that of saturated gas have a subscript $g$. I understand ...
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How can plots showing the mixing line for Schmidt-Appleman criterion (for aircraft contrail formation modeling) show liquid water below triple point?

In trying to understand the Schmidt-Appleman criterion for contrail formation. There is one aspect that I cannot make sense of. In many papers that describe the criterion they include a plot as shown ...
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Phase difference between two waves confusion

I'm facing much confusion about a rather silly problem recently. Suppose I have two functions $\sin(x+\phi_1)$ and $\sin(x+\phi_2)$. Defining $\theta_1=x+\phi_1$ as the phase of the first and $\...
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What is the upper pressure limit for solid to liquid phase border of water on 0.0 °C?

On phase diagram of water, solid to state border is a straight vertical line. Someone can argue it is only an approximation and nature cannot have vertical lines. For me however, it is clearly ...
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2 answers
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Why the specific heat capacity of the same substance is different in its different phase (state of matter)?

Concise Physics ICSE Volume II page 265 mentions the following: The specific heat capacity of the same substance is different in its different phases. The specific heat capacity of water is 4200 J kg^...
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Why is the latent heat of vaporization 0 at the critical point?

This is not a homework question. The critical point of water is $\mathrm{374 \ C}$ and $\mathrm{22.06 \ MPa}$. At the critical point the latent heat of vaporization is $0$ - why? Assume the water ...
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How much heat energy is required to bring 1 liter of water to the critical point?

This is not a homework question. The critical point of water is 374 C and 22.06 MPa. At the critical point the latent heat of vaporization is 0 - why? Assume the water starts at 100 C. If you add the ...
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How do we know that helium is a liquid at absolute zero?

I was looking at a phase chart of helium and like many before me, I was surprised that helium was a liquid at absolute zero: Now there are plenty of explanations online for why it can be liquid ...
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Where can I find pressure-temperature diagrams or phase diagrams for various substances on the internet ? (and for free)

In this particular case, I want to investigate making liquid nitrogen. My compressor will only go to 400 PSI, so I want to know what temperature nitrogen will turn liquid at 400 PSI (and really 350 ...
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I don't understand why for resistors in AC circuits the phase angle between voltage and current is zero

From the following graph I understand it is because they reach the voltage and the current reach their maximum values at the same time on the resistor, but I don't understand why this should be that ...
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Can a liquid forms vapor pressure at 0 degree Celsius? because we know that at freezing point the vapour pressure of both solid and liquid are equal [closed]

How can we able to explain the vapour pressure in between solid and liquid phase in case of freezing point?
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What they really mean with "volume' in phase diagram?

How can phase diagrams involve volume since it is extensive?  perhaps it is understood that we are talking about a specific volume? If the volume and pressure are known but I don't know how much ...
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How do I use the property table for thermodynamics for water?

When to use the saturated water table and when to use the superheated water table? Also, please mention when to use the pressure table and when the temperature table?
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Why vapor pressure exist below saturation temperature? [duplicate]

Say, there is water at $50^{\circ}\text{C}$ at 1 atm pressure on an open pot. Water boils at $100^{\circ}\text{C}$ at that pressure. So there should be no vapor at that condition as well as vapor ...
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Explanation of formation of bubbles when gases reach the hydrostatic pressure in a lake

I am learning about the hydrostatic pressure in a lake, can someone please explain to me why when the gases reach saturation in a lake, there is a formation of bubbles?
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First and second order phase transition classificiation and scope of Landau theory

I am puzzled by the definition of continuous and first-order phase transitions and the use of Landau theory. I think I am lost in technicality. In the phase diagram below the critical point, we have ...
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Understanding the critical temperature on a $pV$ diagram

I know that the critical temperature is the highest possible temperature before a liquid becomes a gas. I also know that at the critical volume on the critical temperature isotherm, $\frac{\partial P}{...
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Is there any substance whose vapor-liquid coexistence area appears leaned?

The usual substance whose vapor-liquid coexistence area appears like that shown in following Fig.1 My question is: is there any substance whose vapor-liquid coexistence area looks leaned, i.e., $V_{...
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Existence of liquid phase of metal below triple point pressure in vacuum chamber

As part of my work, I perform localized heating of metals using a CW laser, upto and past the melting point, inside a vacuum chamber with typical ambient pressures of $\sim 10^{-9}\,$mbar. However, I ...
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Is there a phase diagram for $\rm CO_2$ below 1 millibar?

Considering $\rm CO_2$ snow on Mars and recent cold temperature on the earths' south pole, I am looking for a $\rm CO_2$ phase diagram below 1 millibar that shows the sublimation temperature of $\rm ...
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3 votes
1 answer
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Why can't water be liquid above 647 kelvins?

In this article about vapor, it is said that liquid water can't exist if its temperature is higher than 647 kelvins. But if we put the liquid water in a closed container and heated up the water, ...
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1 answer
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Latent heat of water at triple point

My class textbook states that the latent heat at triple point of water is zero. When i tried to look up there was less to no information about this fact. Can anyone give any plausible explanation for ...
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4 votes
1 answer
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What does 'saturated' air actually mean?

I'm having some problem in getting an insight on what 'saturation with vapor' actually means. The question is asked in the context of atmospheric air becoming saturated with water vapor and beginning ...
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What is implied by the term "phase transition" as in when you boil water?

I have somehow gathered that when you heat water as you record its temperature, it's temperature begins to rise until it boils. After that it's temperature will not rise by adding anymore heat. So ...
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Boiling in completely filled vessel

Suppose we completely fill a vessel with water and then close it in such a way that no matter can escape from it. If we now heat the vessel to 373K then what will happen inside vessel?
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$S$-Parameter Phase in Matlab

I'm trying to plot the phase of S-parameters on Matlab. The data I have is the coupling matrix (M) of the system and from that I have extracted S11 and S21 (column 1 in image is frequency and column 2 ...
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Why was water freezing almost instantaneously when shaking a bottle that spent the night outside during a frosty night?

Due to the forecasted frost last night, I placed yesterday evening, some 1.5l standard PET bottles filled up to 90% with warm tap water(+60°C) close to some vegetables that I wanted to protect in my ...
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What pressure does liquid nitrous oxide need at -45°C?

What pressure does liquid nitrous oxide need at -45°C to remain liquid? How can I calculate it's pressure required for other temperatures?
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Phase Diagrams - Hypereutectic, pro-eutectic phase

While designing some questions for my undergraduate class, I came across a scenario that is having me scratch my head. I am using the Cu-Ag phase diagram and arbitrarily selected Co = 90 wt.% Ag. My ...
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Why does adding salt to the water in a humidifier increase the amount of steam it makes?

Rather than "it decreases the latent heat of vaporization", can you explain why?
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Can the freezing point of Nitrogen be reduced?

There was an interesting Q/A about mixing helium and nitrogen. Is there anything that can be added to liquid nitrogen to reduce it's freezing point to below 63 kelvin?
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1 answer
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How to convert these from the given free energy $G$ vs $X$ to $T$ vs $X$ diagrams?

What I really do not understand is how they are converting from G vs X curves to T vs X. I have a couple of more diagrams with which I am having problems. A detailed answer to this is most welcome.
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Critical point for fusion curve

In phase diagram, on vaporization curve there exists a critical point beyond which a gas can not be liquifies but why does fusion curve does NOT end at a critical point and continues to infinity?
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Properties of water at a temperature of 300°C and a pressure of 3000 kPa

I'm using a online calculator, and it says that the boiling point of water at a pressure of 3000 kPa is 233.7°C. So then I understand that the water in is a superheated state (and thus still a liquid)....
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Where does the mass go in Clausius-Clapeyron approximation for ideal gases?

I am currently studying Clausius-Clapeyron equation at university. One of the proposed problems asked us to find the latent heat of vaporisation of camphor using ideal gas laws. In the solution by my ...
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R134a state at rest

I'm a mechanic and I've had a question for some time regarding AC systems that no one in my garage seems to be able to answer (or care actually). R134a has a boiling point at -26°C at atmospheric ...
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Is it possible to have three stable liquid phases in a binary mixture?

With this system, it would be possible to have three liquid phases and two liquid-liquid coexistence regions at various compositions. Similar behaviour is common for solids such as alloys, sometimes ...
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3 answers
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Why are there two states of matter in a bottle of gas?

Say a bottle of natural gas used for heating or cooking. There is a liquid phase, which I believe is the densest part, at the bottom of the bottle. And on top of it, there is presumably gas in a ...
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4 votes
2 answers
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Does the density of ice increase further when it is further cooled?

As we know, water becomes ice at $0^°$C. After becoming ice, if we lower the temperature further ($<0^°$C), then does the density of ice increase further? If yes, in that case, does the volume ...
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1 answer
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How can Water exist in two different liquid states at the atomic scale?

We know how unique water is and this question is based on a recent discovery that water can exist in two different liquid states. The density of the two states vary by almost 20 %. Can someone explain ...
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Shouldn't the projection on the y-axis, of a radial vector in a circle making an angle theta with the x axis, also be the radius?

I don't understand this diagram... the projection is meant to be a shadow, right? So shouldn't the shadow of the radial vector as shown in the circle on the y-axis, be the entire y-axis (since the ...
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First-Order Phase Transition

When the density/volume abruptly changes (isobar/isothermal) while providing a sufficient latent heat to the system, is this variation related to a high compression/expansion as it is illustrated to ...
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Understanding liquid-liquid phase separation

The above figure shows how the regular-solution free energy might lead to liquid–liquid equilibrium. In the region between the compositions $x^I_A$ and $x^{II}_A$, $G$ increases with $x_A$. If the ...
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Liquid-Vapour Surface Tension

In a multi-phase system with a liquid which meets a gas at the free surface, one can define liquid-vapour surface tension $\gamma_{LV}$: is this surface tension a constant when one varies the pressure ...
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