Kelvin temperature absolute zero

Lord Kelvin (1824-1907). The Kelvin temperature scale has an absolute zero. True comparisons can be made using the Kelvin scale. A substance at a temperature of 400 Kelvins contains particles with twice as much kinetic energy as a substance at 200 Kelvins. Absolute zero is the temperature where the random motion of particles in a substance stops. It is the absence of temperature. Absolute zero is equivalent to —273.16°C. How this value is determined is discussed shortly after we discuss our next gas law. The relationship between Kelvin and Celsius temperature is... 

Absolute temperature temperature measured on a scale with absolute zero as 0. This is conventionally measured in kelvin, where absolute zero corresponds to 0 K (—273.15°C or -459.67°F). 

The Kelvin temperature scale has as its zero point absolute zero, the theoretical temperature at which the molecules of a substance have the lowest energy. This temperature, absolute zero, corresponds to -273.15 on the Celsius scale and to -459.67 on the Fahrenheit scale. 

Lord Kelvin, a British physicist, noticed that an extension of the different temperature-volume lines back to zero volume (dashed line) yields a common intercept at —273.15°C on the temperature axis. Kelvin named this temperature absolute zero. The degrees are the same size over the entire scale, so 0°C becomes 273.15 degrees above absolute zero. In honor of Lord Kelvin s work, this scale is called the Kelvin temperature scale. As pointed out in Section 1-12, the relationship between the Celsius and Kelvin temperature scales is K=°C 4- 273.15°. 

Temperature kelvin K Absolute zero is 0 K triple point of water is 273.16 K. 

Kelvin are obtained by adding 273 degrees to the Centigrade temperature (if above 0°C), or subtracting the Centigrade temperature from 273 (if below 0°C). Degrees Rankine are obtained by subtracting 460 from the Fahrenheit temperature. Absolute zero is the temperature at which the volume of a perfect gas theoretically becomes zero and all thermal motion ceases, which occurs at -273.13°C, or -459.4°F. 

Kelvin Scale A temperature scale that uses Centigrade degrees but makes the zero degrees signify absolute zero— -273.16°C (-459.69°F). Thus, K = °C + 273.16. See temperature temperature, absolute zero, keratin A filler that is based on calcined feathers, hog bristles, and the like. It is sometimes used in place of wood flour. See filler. 

Kelvin (K) The standard unit of thermodynamic temperature. Zero degrees Kelvin represents absolute zero. Water freezes at 273 K and water boils at 373 K under standard pressure conditions. 

Temperature is usually measured in Celsius (°C), Fahrenheit (°F) or Kelvin (K). The Celsius and the Fahrenheit scales are empirical but (as we shall see in Chapter 3) the Kelvin scale is the absolute scale based on the second law of thermodynamics. Zero degrees Kelvin is absolute zero, the lowest possible temperature. Temperatures measured in these scales are related as follows ... 

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

The volume of a gas would theoretically be zero at a temperature of approximately -273°C or -460°F. Tliis temperature, wliich lias become known as absolute zero, is tlie basis for tlie definition of two absolute temperature scales, tlie Kelvin (K) and Rankine (°R) scales. The former is defined by shifting tlie Celsius scale by 273-Celsius degrees so that 0 K is equal to -273°C. Equation (4.2.3) shows tliis relation. 

Carnot s research also made a major contribution to the second law of thermodynamics. Since the maximum efficiency of a Carnot engine is given by 1 -T( H, if the engine is to be 100 percent efficient (i.e., Cma = 1), Tc must equal zero. This led William Thomson (Lord Kelvin) to propose in 1848 that Tf must be the absolute zero of the temperature scale later known as the absolute scale or Kelvin scale. ... 

In the study of refrigeration, the Kelvin or absolute temperature scale is also used. This starts at absolute zero and has the same degree intervals as the Celsius scale, so that ice melts at + 2 73.16 K and water at atmospheric pressure boils at + 373.15 K. 

Absolute temperature, 57 Kelvin scale, 58 Absolute zero, 58... 

The maximum amount of work obtainable from a given quantity of heat, called its motivity by Lord Kelvin (1852), is thus always less than the mechanical equivalent of the quantity of heat, except in the limiting case when the refrigerator is at absolute zero (T2 = 0). It cannot be specified in terms of the condition of the body from which the heat is taken, or into which the heat passes, but requires in addition a knowdedge of the lowest available temperature, T2. For if we had another body at temperature T0, where T0 < T2, which could be used as a refrigerator, the amount of work ... 

Equation (4.2) requires that the total area above 0 Kelvin be obtained, but heat capacity measurements cannot be made to the absolute zero of temperature. The lowest practical limit is usually in the range from 5 K to 10 K, and heat capacity below this temperature must be obtained by extrapolation. In the limit of low temperatures, Cp for most substances follows the Debye low-temperature heat capacity relationship11 given by equation (4.4)... 

Absolute temperature The lowest possible temperature is absolute zero. The absolute temperature scale starts there and increases in increments of 1 degree Celsius. The unit of measurement is the kelvin (K). 

The graphical plot of the temperature versus volume of a gas produces a straight line. If several different gases are studied and the temperature-volume data is plotted, the extrapolations of these graphs all intersect at the same temperature, -273°C. The Kelvin equivalent of this temperature is expressed as 0 K, or absolute zero. The mathematical expression to change Celsius temperature to Kelvin is K = C° + 273°. 

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. 

Kelvin then replotted his data, this time extrapolating each graph till the volume of the gas was zero, which he found to occur at a temperature of -273.15 °C see Figure 1.5. He then devised a new temperature scale in which this, the coldest of temperatures, was the zero. He called it absolute zero, and each subsequent degree was equal to 1 °C. This new scale of temperature is now called the thermodynamic (or absolute) scale of temperature, and is also sometimes called the Kelvin scale. 

Celsius degrees and Kelvin degrees are the same size. The Kelvin scale begins at absolute zero. This is the temperature at which the particles in a substance have no kinetic energy. Therefore, Kelvin temperatures are never negative. By contrast, 0°C is set at the melting point of water. Celsius temperatures can be positive or negative. 

Kelvin scale a temperature scale that begins at the theoretical point of absolute zero kinetic energy, or -273.15°C each unit (a kelvin) is equal to 1°C... 

Absolute zero. Minus 273°C or minus 460 or 0°K or Kelvin, the scale used in theoretical physics and chemistry. Absolute zero is the theoretical temperature at which all molecular activity ceases. In practical terms, the lowest reachable temperature is about 1°K. 

When a gas is cooled by 1 °C, from 0°C to —1 °C, it loses l4 3 of its pressure. Since pressure is due to movement of the gas molecules, Lord Kelvin realised that a gas would have no pressure at -273 °C that is, there would be no movement of the gas molecules -273 °C is absolute zero. Since the rate of a reaction depends upon the movement and hence collision of molecules, the relevant temperature scale for chemical (and therefore biochemical) reactions is one whose zero is -273 °C. It is known as the Kelvin or absolute scale. 

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