Triple point The temperature and pressure at which

Triple point The temperature and pressure at which the solid, liquid, and vapor phase of a substance can coexist in equilibrium, 233 Tryptophan, 622t Tyrosine, 622t... 

TRIPLE POINT. The temperature and pressure at which the solid, liquid, and vapor of a substance are in equilibrium with one another. Also applied to similar equilibrium between any three phases, Le., two solids and a liquid, etc. The triple point of water is +0.072 C at 4.6 mmHg it is of special importance because it is the fixed point for the absolute scale of temperature. 

What other properties characterize a gas Recall the generic phase diagram for a pure substance. Figure 5.31. What landmarks do all substances have in common Every substance has a triple point - the temperature and pressure at which all three... 

Phase diagram of water (not to scale). The curves and line represent the temperatures and pressures at which phases are in equilibrium. The triple point is at 0.0rC, 4.56 mm Hg the critical point is at 374°C. 

Phase diagrams are constructed by measuring the temperatures and pressures at which phase changes occur. Approximate phase diagrams such as those shown in Figures 11-39 and 11-40 can be constmcted from the triple point, normal melting point, and normal boiling point of a substance. Example illustrates this procedure. 

Sublimation and deposition happen only at very low temperatures and pressures, below what scientists call the triple point. The triple point is the temperature and pressure at which the solid,... 

Two other special features on the diagram are designated by black dots. The dot at point D, known as the critical point, represents the critical temperature and the critical pressure (the point at which the liquid state no longer exists, regardless of the amount of pressure). The other dot represents the intersection of the three lines, known as the triple point. The triple point represents the temperature and pressure at which all three phases coexist simultaneously. 

The correct answer is (D). Because the triple point represents the temperature and pressure at which solid, liquid, and gas all coexist, the vapor pressures will be identical at this point. 

Point A on the phase diagram of water is the triple point for water. The triple point is the point on a phase diagram that represents the temperature and pressure at which three phases of a substance can coexist. All six phase changes can occur at the triple point freezing and melting evaporation and condensation sublimation and deposition. Point B is called the critical point. This point indicates the critical pressure and critical temperature above which water cannot exist as a liquid. If water vapor is at the critical temperature, an increase in pressure will not change the vapor into a liquid. 

The curves intersect at A, the triple point, which is the temperature and pressure at which all three phases of a substance exist in equilibrium. 

The relationships among the phases of a single substance are illustrated by a phase diagram, in which each region represents a pure phase and the boundaries between the regions show the temperatures and pressures at which the two phases are in equilibrium. At the triple point, aU three phases are in equilibrium. 

The segment BD divides the liquid and the gas phases in the graph. It also denotes the vapor pressures at different temperatures. The intersecting point of the curves represented by point B is called the triple point. This point represents the temperature and pressure at which the three phases of a substance are in equilibrium. How many triple points are likely to exist for a substance The answer is one. There is only one pair of temperature-pressure combination for a substance at which the three states will be in equilibrium. Figure 7-6 shows a phase diagram representing the majority of other compounds that we see in nature. 

The temperature and pressure at which three phases of a substance are in equilibrium is known as a triple point. The three phases can be solid, liquid, and gas, but can also be two solid phases (different arrangements of the molecules in the solid) and a liquid phase. 

The authors refer to these phase diagrams as having a triple point, although the intersection of the two equilibrium lines between the liquid crystalline phases and the isotropic melt should not be unique to the (temperature and) pressure at which the experiments were conducted. 

Kelvin kel-von [William Thomson, Lord Kelvin (1824-1907)] (1968) (K) n. The SI unit of both temperature and difference between temperatures, equal to 1/273.16 of the thermodynamic triple point of water, i.e., the temperature and pressure at which all three phases of water - ice, liquid, and vapor - are in equilibrium. A change or difference of 1K is exactly equal to 1° difference on the Celsius (formerly centigrade) scale, and the temperature 0°C corresponds to 273.15 K. Symbol K the name degree of Kelvin (symbol K) was discontinued by international agreement in 1967. 

Figure 4.5 Phase diagram for a single pure compound, i.e., C = 1 in the Gibbs Phase Rule so F = (3-P). The curved lines indicate the temperatures and pressures at which two phases (P = 2) can co-exist in equilibrium, i.e., F = 1, so once either temperature or pressure is specified for such a system the other is fixed at an equilibrium value. The areas marked gas , Uquid and soUd are single phase regions (P = 1) so F = 2, i.e., both temperature and pressure can be varied within each of these regions without changing the number of phases present. If three phases are to co-exist at equilibrium (P = 3) then F = zero, i.e., there is only one unique combination of temperature and pressure at which this is possible this is the triple point (TP) for this compound. The point CP is the critical point for temperatures and pressures that are both greater than the critical values there is no longer any distinction between gas and liquid phases.

The curve AD that divides the soUd region from the gaseous region gives the vapor pressures of the sohd at various temp atures. This curve intersects the other curves at point A, the triple point, which is the point on a phase diagram representing the temperature and pressure at which three phases of a substance coexist in equilibrium. For water, the triple point occurs at 0.01°C, 0.00603 atm (4.58 mmHg), and the solid, liquid, and vapor phases coexist. ... 

As shown in the flowsheet in Figure 3.30, cooled seawater is admitted to the freezer at low pressure. The conditions in the freezer are the triple point for seawater the temperature and pressure at which ice, brine, and steam coexist. Heat is removed from the freezer by vaporizing water. Water vapor is compressed and heat is delivered to the melter by the condensation of water vapor. 

Helium is the only liquid which cannot be frozen by the reduction of temperature alone. Pressure must also be applied. It is also the only substance lacking a triple point , i.e. a combination of temperature and pressure at which solid, liquid and gas coexist in equilibrium. 

D line represents the variation in the melting point with pressure. The A to B line represents the variation of the vapor pressure of a liquid with pressure. This B point shown on this phase diagram is the critical point of the substance, the point beyond which the gas and liquid phases are indistinguishable from each other. At or beyond this critical point, no matter how much pressure is applied, it is not possible to condense the gas into a liquid. Point A is the triple point of the substance, the combination of temperature and pressure at which all three states of matter can exist. 

Carbon dioxide plays a central role in the CNG process both as a pure component and in mixture with other compounds. The triple point of carbon dioxide is referred to frequently in the following discussion it is the unique temperature and pressure at which solid, liquid, and vapor phases of carbon dioxide can exist at equilibrium (-56.6°C, 5.1 atm). The carbon dioxide triple point is shown in Figure 2, a phase diagram for carbon dioxide. 

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