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For this reason, KF is unsuitable for solutions containing e.g. dimethyl sulfoxide. KF has a high accuracy and precision, typically within 1% of available water, e.g. 3.00% appears as 2.97–3.03%. Although KF is a destructive analysis, the sample quantity is small and is typically limited by the accuracy of weighing.
Food moisture analysis is the determination of the concentration of water in a food sample. A variety of techniques may be used including Karl Fischer titration and loss on drying. Many technical standards exist which define test methods for determining moisture in different types of food.
If the volatile content of the solid is primarily water, the loss on drying technique gives a good measure of moisture content. [5] Because the manual laboratory method is relatively slow, automated moisture analysers have been developed that can reduce the time necessary for a test from a couple of hours to just a few minutes.
Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 (completely dry) to the value of the materials' porosity at saturation.
An EPA scientist samples water in Florida Everglades. Samples of water from the natural environment are routinely taken and analyzed as part of a pre-determined monitoring program by regulatory authorities to ensure that waters remain unpolluted, or if polluted, that the levels of pollution are not increasing or are falling in line with an agreed remediation plan.
The general expression Qualitative Analysis [...] refers to analyses in which substances are identified or classified on the basis of their chemical or physical properties, such as chemical reactivity, solubility, molecular weight, melting point, radioactivity properties (emission, absorption), mass spectra, nuclear half-life, etc. Quantitative Analysis refers to analyses in which the amount ...
in the condensation of the water-vapour of the air on the cold surface of a glass; in the capillarity of hair, wool, cotton, wood shavings, etc.; in the imbibition of water from the air by gelatine; in the deliquescence of common salt; in the absorption of water from the air by concentrated sulphuric acid; in the behaviour of quicklime". [4]
In thermodynamics, the cryoscopic constant, K f, relates molality to freezing point depression (which is a colligative property).It is the ratio of the latter to the former: