Kelvin expressions

This minimum value should be constant for a given adsorptive at a given temperature, irrespective of the nature of the adsorbent. Any liquid present in pores finer than those given by r, of the appropriate Kelvin expression... 

The total energy of the surface, therefore, consists of two terms, of which one represents the amount of work done against surface tension, and the other the inflow of heat during the extension of the surface. If we call this total energy A, the following equation, given by Kelvin, expresses the connection between surface tension and total energy at any temperature —... 

The Kelvin expression for capillary condensation on the inner wall of a cylindrical pore is found by substitution of... 

Kelvin expresses doubts that both Carnot and Joule can be right also introduces the term Thermodynamics. 

FIGURE 2 12 Boiling points of unbranched alkanes and their 2 methyl branched iso mers (Temperatures in this text are expressed in de grees Celsius C The SI unit of temperature is the kelvin K To convert degrees Celsius to kelvins add 273 15 )... 

The coefficient k, expressed in J sec cm is the quantity of heat in joules, transmitted per second through a sample one centimeter in thickness and one square centimeter in area when the temperature difference between the two sides is one degree kelvin (or Celsius). The tabulated values are in microjoules. To convert to microcalories, divide values by 4.184. To convert to mW m divide values by 10. 

As already indicated in Section 3.1, the study of mesoporous solids is closely bound up with the concept of capillary condensation and its quantitative expression in the Kelvin equation. This equation is, indeed, the basis of virtually all the various procedures for the calculation of pore size... 

In this expression, cos 0 is the average value of cos 0 the weighting factor used to evaluate the average is given by the Boltzmann factor exp(-V /RT), where R is the gas constant in the units of and T is in degrees Kelvin. Note that the correction factor introduced by these considerations reduces to unity if... 

Remember that in this relationship, as in all thermodynamic equations, temperature must be expressed in degrees Kelvin. 

The temperature is expressed ia degrees Celsius. The empirical equation for the Gibbs free energy change was found to be linear with temperature for AG° ia kJ/mol, Tia Kelvin. 

The rate of this reaction is significantly enhanced over catalysts such as copper chloride which is the basis for the Deacon process for producing CI2 from HCl. The relationship between the equilibrium constant and the temperature in Kelvin for the reaction is expressed by equation 19. 

Vitreous sihca does not react significantly with water under ambient conditions. The solution process involves the formation of monosilicic acid, Si(OH)4. Solubihty is fairly constant at low pH but increases rapidly when the pH exceeds 9 (84—86). Above a pH of 10.7 sihca dissolves mainly as soluble sihcates. Solubihty also increases with higher temperatures and pressures. At 200—400°C and 1—30 MPa (<10 300 atm), for example, the solubihty, S, of Si02 in g/kg H2O can be expressed as foUows, where d ls the density of the vapor phase and T is the absolute temperature in Kelvin. 

Vitreous siUca aimealed at 1100°C has been designated NIST Standard Reference Material 739 (LI and L2). Its expansion coefficient, a, may be calculated for 300—700 K from the following expression (144), where Tis the absolute temperature in Kelvin. 

Celsius temperature degree Celsius °c equal to kelvin and used in place of kelvin for expressing Celsius temperature, t, defined by equation t = T — where T is the thermodynamic temperature and Tq = 273.15 K by definition... 

A sohdus indicates the quotient of two unit symbols and the word per the division of two unit names m/s for meter per second. The horizontal line or negative powers are also permissible. The sohdus or the word per is not repeated in the same expression, eg, acceleration as m/s for meter per second squared and thermal conductivity as W/(m-K) for watt per meter kelvin. 

Temperatures are expressed in kelvins heats of vaporization, in J/kmol. 

Temperatures are expressed in kelvins hquid heat capacities are in J/kmol-K. 

Absolute The temperature relative to absolute zero, expressed in Kelvin. Also called thermodynamic temperature. 

It is usual these days to express all physical quantities in the system of units referred to as the Systeme International, SI for short. The International Unions of Pure and Applied Physics, and of Pure and Applied Chemistry both recommend SI units. The units are based on the metre, kilogram, second and the ampere as the fundamental units of length, mass, time and electric current. (There are three other fundamental units in SI, the kelvin, mole and candela which are the units of thermodynamic temperature, amount of substance and luminous intensity, respectively.)... 

For ready identification, actual temperature levels are expressed in degrees Celsius (°C) while temperature difference, interval or gradient is expressed in Kelvin (K). 

Thermal conductance defines a material s ability to transmit heat measured in watts per square meter of surface area for a temperature gradient of one Kelvin in terms of a specific thickness expressed in meters. Its dimensions are therefore W/m K. 

The value of an insulant to reduce heat flow is expressed as resistivity or its reciprocal conductivity. The units of the latter are watts per metre kelvin (W/ (m K)). Values for these materials used are approximately as follows ... 

The temperature of a gas is ordinarily measured using a thermometer marked in degrees Celsius. However, as we will see in Section 5.2, in any calculation involving the physical behavior of gases, temperatures must be expressed on the Kelvin scale. To convert between °C and K, use the relation introduced in Chapter 1 ... 

Typically, in gas law calculations, temperatures are expressed only to the nearest degree. In that case, the Kelvin temperature can be found by simply adding 273 to the Celsius temperature. 

A ten-gallon methane tank contains 1.243 mol of methane (CH4) at 74°F. Express the volume of the tank in liters, the amount of methane in the tank in grams, and the temperature of the tank in Kelvin. 

The boiling points and freezing points in degrees Centigrade of certain liquids are listed below. Express these temperatures on the absolute temperature (degree Kelvin) scale. 

Why is it desirable to express all temperatures in degrees Kelvin when working with problems dealing with gas relationships ... 

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