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Sodium hydroxide is insoluble in ether and other non-polar solvents. Similar to the hydration of sulfuric acid, dissolution of solid sodium hydroxide in water is a highly exothermic reaction [15] where a large amount of heat is liberated, posing a threat to safety through the possibility of splashing. The resulting solution is usually colorless ...
A velocity-type meter measures the velocity of flow through a meter of known internal capacity. The speed of the flow can then be converted into a volume of flow to determine the usage. There are several types of meters that measure water flow velocity, including jet meters (single-jet and multi-jet), turbine meters, propeller meters and mag ...
A hygrometer is an instrument which measures the humidity of air or some other gas, that is, how much water vapor it contains. [1] Humidity measurement instruments usually rely on measurements of some other quantities such as temperature, pressure, mass, and mechanical or electrical changes in a substance as moisture is absorbed.
Eventually, the word hygroscope ceased to be used for any such instrument in modern usage, but the word hygroscopic (tending to retain moisture) lived on, and thus also hygroscopy (the ability to do so). Nowadays an instrument for measuring humidity is called a hygrometer (hygro-+ -meter).
Because they are used for domestic water measurement, piston meters, also known as rotary piston or semi-positive displacement meters, are the most common flow measurement devices in the UK and are used for almost all meter sizes up to and including 40 mm (1 + 1 ⁄ 2 in). The piston meter operates on the principle of a piston rotating within a ...
Specific volume is the volume of the mixture (dry air plus the water vapor) containing one unit of mass of "dry air". The SI units are cubic meters per kilogram of dry air; other units are cubic feet per pound of dry air. The inverse of specific volume is usually confused as the density of the mixture. [11]
The lower compartment of the desiccator contains lumps of silica gel, freshly calcined quicklime, Drierite, molecular sieves, phosphorus pentoxide, (not as effective) anhydrous calcium chloride, or other desiccant to absorb water vapor. The substance needing desiccation is put in the upper compartment, usually on a glazed, perforated ceramic plate.
A hygroscopic substance used to induce or sustain a state of dryness or desiccation (i.e. the absence of moisture) in its vicinity by abstracting water molecules from other substances. Desiccants come in many different forms and work by many different principles, ranging from simple absorption to the chemical bonding of water molecules.