Pressure Phase Diagrams

The occurrence of different phases of a one component system can be shown on a pressure temperature.

The phases present in a one line system at various temperatures can be conveniently presented on a P- versus-T diagram. An example is provided by the diagram for water for moderate pressures and temperatures. The lien labeled TC shows the pressures and temperatures of liquid and vapour exist in the equilibrium. It is a vapour-pressure curve. At temperatures higher than that of point C, the critical point, liquid vapour pressure does not occur. Therefore this liquid vapour equilibrium line finishes at C.

Consider the changes that occur as a pressure or temperature change results in the system moving in the lien TC. From point 1, for instance, the temperature can be maintained lesser to get to point 2, or the pressure can be increased to get to point 3. In either process one crosses the liquid vapour equilibrium line in the direction of consideration from the vapour to liquid. Notice, however, that if a sample phase carried from point 1 to point 2 or point 3 by a path that goes around C, no phase change will occur.

Line TB gives the temperature and pressure at such solid and vapour are in equilibrium; i.e. it is the curve for the vapour pressure of the solid line TA gives the temperatures and pressures at which ice as a function of pressure equilibrium; i.e. it represents the melting point of ice as a function of pressure. Liquid water can be cooled below its freezing point to give, as indicated by the system. It shows its existence to the fact that the rate of formulation of ice has been interfered with by the use of a very clean sample of water and a smooth container.

It is a convenient representation of all the available information about the phases of water that occurs at moderate pressures and temperatures. It shows the phase behavior of water at very large pressures. Many new phases, corresponding to ice with different crystal structures, are of common and is known as polymorphism. It is particularly remarkable that the melting point of ice VII, which exists above about 20,000 bar pressure, is over 100 degree C.

The most well-known material water that we have utilized as an illustration of P-versus-T phase diagrams is, in some ways, not at all representative. More suitable, in this regard, is one of the solid liquid equilibrium line, TA has a positive slope.

   Related Questions in Chemistry

  • Q : Problem on Clausius equation of state

    If a gas can be described by the Clausius equation of state: P (V-b) = RT Where b is a constant, then:  (a) Obtain an expression for the residual vo

  • Q : Explain Vapour Pressure Composition A

    A pressure composition diagram for a liquid vapor system can be used to show the composition of the liquid and equilibrium vapor.Vapor equilibrium data are useful in the study of distillations. It is of value to have diagrams showing not only the vapor pre

  • Q : Mole fraction of Carbon dioxide Choose

    Choose the right answer from following. If we take 44g of CO2 and 14g of N2 what will be mole fraction of CO2 in the mixture: (a) 1/5 (b) 1/3 (c) 2/3 (d) 1/4

  • Q : How haloalkanes are prepared from

    Alkyl halides can be prepared from alkanes through substitution and from alkenes through addition of halogen acids or through allylic substitution.    From alkanesWhen alkanes are treated with halogens, chlo

  • Q : Unit of mole fraction Provide solution

    Provide solution of this question. Unit of mole fraction is: (a) Moles/litre (b) Moles/litre2 (c) Moles-litre (d) Dimensionless

  • Q : Question on seminormal solution Provide

    Provide solution of this question. The weight of sodium carbonate required to prepare 500 ml of a seminormal solution is: (a) 13.25 g (b) 26.5 g (c) 53 g (d) 6.125 g

  • Q : Problem on relative humidity Relative

    Relative humidity is the ratio of the partial pressure of water in air to the partial pressure of water in air saturated with water at the same temperature, stated as a percentage: Relative  =

    Q : Relative lowering of the vapour pressure

    Choose the right answer from following.The relative lowering of the vapour pressure is equal to the ratio between the number of: (a) Solute moleules and solvent molecules (b) Solute molecules and the total molecules in the solution (c) Solvent molecules and the tota

  • Q : Ionization Potential Second ionization

    Second ionization potential of Li, Be and B is in the order (a)Li>Be>B (b)Li>B>Be (c)Be>Li>B (d)B>Be>Li

  • Q : Decinormal concentration of Sulfuric

    Give me answer of this question. The volume of water to be added to 100cm3 of 0.5 N N H2SO4 to get decinormal concentration is : (a) 400 cm3 (b) 500cm3 (c) 450cm3 (d)100cm3

©TutorsGlobe All rights reserved 2022-2023.