Units of temperature

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 )... 

In 1954, the 10th CGPM added the degree Kelvin as the unit of temperature and the candela as the unit of luminous intensity. At the time of the 11th CGPM in 1960, this new system with six base units was formalized with the tide International System of Units. Its abbreviation in all languages is SI, from the French l e Sjstume International d Unitus. 

Extensive tabulations of Antoine parameters are available for many chemicals of importance to engineers, chemists, and environmental scientists (9,19,20). Caution is in order when using tabulated Antoine constants because several forms of the correlating equation are found in the Hterature. In particular, there are variations in the sign before the second term, the units of temperature, and the use of natural or decimal logarithms of the vapor pressure. 

For many purposes in chemistry, the most convenient unit of temperature is the ketvin (K) note the absence of the degree sign. The kelvin is defined to be 1/273.16 of the difference between the lowest attainable temperature (0 K) and the triple point of water (0.01°C). The relationship between temperature in K and in °C is... 

Cell voltage Voltage associated with an electrochemical cell, 485-486,489 Celsius degree (°C) Unit of temperature... 

The quantity (hcCb/k) has the units of temperature. It is often written as the Einstein temperature, in which case... 

Kekule structures Two Lewis structures of benzene, consisting of alternating single and double bonds, kelvin (K) The SI unit of temperature. See also Appendix IB. 

Note particularly that the equation has no temperature change in it and that the enthalpy of fusion term has no unit of temperature in it. 

The XIII Conference Generale des Poids et Mesures adopts the Kelvin scale with a single fixed point 273.16K. The unit of temperature is designated Kelvin its symbol is K. 

Care must be taken to ensure that the correlation equations are applied correctly, especially since the units of the property, the units of temperature and whether the logarithm is base e or base 10. The equations should not be used to extrapolate beyond the stated temperature range. 

In a similar way, the Systeme Internationale has defined other common physicochemical variables. The SI unit of temperature T is the kelvin. We define the kelvin as 1/273.16th part of the thermodynamic temperature difference between absolute zero (see Section 1.4) and the triple point of water, i.e. the temperature at which liquid water is at equilibrium with solid water (ice) and gaseous water (steam) provided that the pressure is 610 Pa. 

This has exactly the same significance as the preceding equation, but the constants are grouped in /, which has the units of temperature and will be positive if the reaction is exothermic. 

Given the Arrhenius equation for a reaction, i.e., given the preexponential factor A and the activation energy E as well as the applicable temperature range, k can be found at any temperature within the range. The calculation is not complicated but one must (i) maintain consistency between units, and (ii) be especially careful about the unit of temperature (which must be converted to kelvins). 

Karl Fischer titration A sensitive technique for determining water, based on the reaction of HzO with an amine, I2, S02, and an alcohol, kelvin, K Absolute unit of temperature defined such that the temperature of water at its triple point (where water, ice, and water vapor are at equilibrium) is 273.16 K and the absolute zero of temperature is 0 K. Kieselguhr German term for diatomaceous earth, which was formerly used as a solid support in gas chromatography. 

DEGREE CELSIUS (°C). One unit of temperature on the Celsius temperature scale, which is derived from the thermodynamic of Kelvin scale of temperature and related by Temperature (degrees Celsius) equals Temperature (Kelvin units) minus 273.15. See Temperature. 

The most commonly used thermometers in a laboratory are alcohol-in-glass. However, mercury in-glass thermometers can be used but should be handled with great care. The mercury inside them is poisonous and should not be handled if a thermometer breaks. The units of temperature are those of the Celsius scale. This scale is based on the temperature at which water freezes and boils, that is ... 

Temperature is an independent dimension which cannot be defined in terms of mass, length, and time. The SI unit of temperature is the kelvin (K), defined as 1/273.16 times the triple point temperature of water (the temperature at which ice, liquid water, and water vapor coexist at equilibrium). 0 K is the absolute zero of temperature. 

The SI unit of temperature is so defined that 0 K is the absolute zero of temperature. The SI or Kelvin scale is often called the absolute temperature scale. Although absolute zero does not appear to be attainable, it has been approached to within 10-4 K. 

Two types of bridge circuits (unbalanced and balanced) are utilized in resistance thermometer temperature detection circuits. The unbalanced bridge circuit (Figure 9) uses a millivoltmeter that is calibrated in units of temperature that correspond to the RTD resistance. 

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