kelvin |
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Kelvin (K) is the SI base unit of thermodynamic temperature. The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. The unit is named after the British scientist Sir. W. Thompson, Lord Kelvin (1824-1907). |
ketones |
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Ketones are compounds in which a carbonyl group is bonded to two carbon atoms: R1R2C=O (neither R may be H). They are derived by oxidation of secondary alcohols. The simplest member of the series is acetone, (CH3)2CO. |
kilogram |
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Kilogram (kg) is the SI base unit of mass; it is equal to the mass of the international prototype of the kilogram.
The prototype of the standard is a cylinder of platinum-iridium alloy, 39 mm in diameter and 39 mm high. Prototype of the kilogram kept by the Bureau International des Poids et Mesures (International Bureau of Weights and Measures) at S?evres, near Paris. |
Kjeldhal flask |
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Kjeldhal flask is a round bottom flask with a long wide neck that is used in the determination of nitrogen by Kjeldhal's method. |
Kjeldhal's method |
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Kjeldhal's method is an analytical method for determination of nitrogen in certain organic compounds. The method was developed by the Danish chemist Johan Kjeldahl (1849-1900).
It involves addition of a small amount of anhydrous potassium sulfate to the test compound, followed by heating mixture with concentrated sulfuric acid, often with a catalyst such as copper sulfate. As a result ammonia is formed. After alkalyzing the mixture with sodium hydroxyde, the ammonia is separated by distilation, collected in standard acid, and the nitrogen determined by back-titration. |
Knudsen number |
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Knudsen number (Kn) is a dimensionless quantity used in fluid mechanics, defined by
Kn = λ/l
where λ is mean free path and l is length. |
Kohlrausch's law |
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If a salt is dissolved in water, the conductivity of the solution is the sum of the conductances of the anions and cations. The law, which depends on the independent migration of ions, was deduced experimentally by German chemist Friedrich Kohlrausch (1840-1910). |
