CHEMISTRY GLOSSARY
volumetric flask → odmjerna tikvica
Volumetric flasks are bottles made of glass, in a pear like in shape with long thin necks and flat bottoms. All come with a ground glass stopper for a tight seal. Volume marking is cut in glass with fluoride acid around the neck, so that parallax should be avoided (flask is put in front of the eyes so that one can see only a straight horizontal line). A volumetric flask is calibrated to contain (TC or In) the indicated volume of water at 20 °C when the bottom of the meniscus is adjusted to just rest on the center of the line marked on the neck of the flask. They are used for preparing the exactly known volume of sample solution and standard solutions of reagents. On each flask with volume designation a temperature on which the flask has been calibrated is designated.
Buchner flask → Buchnerova tikvica
Büchner flask (also known as a vacuum flask, filter flask, side-arm flask or Kitasato flask) is a thick-walled Erlenmeyer flask with a side arm to which a vacuum can be applied.
Dewar flask → Dewarova posuda
Dewar flask or vacuum bottle is a container for storing hot or cold substances. It consists of two flasks, one placed inside the other, with a vacuum between. The vacuum prevents the conduction of heat from one flask to the other. For greater efficiency the flasks are silvered to reflect heat. The substance to be kept hot or cold, e.g., liquid air, is contained in the inner flask. The flask is named after British chemist and physicist Sir James Dewar (1842-1923). Dewar invented the Dewar flask in 1892 to aid him in his work with liquid gases. The common thermos bottle is an adaptation of the Dewar flask.
Erlenmeyer flask → Erlenmeyerova tikvica
Erlenmeyer flask is a glass container which has a narrow, cylindrical mouth and a cone-shaped main body that ends in a wide, flat bottom. It was named after its inventor, a German chemist Richard Erlenmeyer (1825-1909). Erlenmeyer flasks are most often used in titrations to hold the liquid that is being titrated.
filter flask → boca za odsisavanje
Filter flask, also known as a vacuum flask, is a flask with a side arm to which a vacuum can be applied. It usually have heavy side walls to withstand high vacuum.
Kjeldahl flask → Kjeldahlova tikvica
Kjeldahl flask is a round bottom flask with a long wide neck that is used in the determination of nitrogen by Kjeldahl’s method. The method was developed by the Danish chemist Johan Kjeldahl (1849-1900).
volumetric pipette → prijenosna pipeta
Volumetric pipettes (transfer or belly pipette) are used in volumetric analysis, when there is a need for taking exact smaller volume of a sample solution or reagent. The upper tube of volumetric pipette has a ringlike marking (mark) which marks its calibrated volume. Pipettes calibrated to deliver (TD or Ex) the indicated volume. By sucking in (with mouth, propipette or a water pump) the liquid is pulled in a little bit above the mark and the opening of the pipet is closed with a forefingertip. Outer wall of pipet is wiped and, with a slight forefinger loosening, the liquid is released until it reaches the mark. Mark must figure as a tangent on a lower edge of the liquid meniscus. A pipette is emptied out by lifting the forefinger off and letting the liquid flow out of the pipette freely. After another 15 s and the tip of the pipette is pulled onto the inner wall of the vessel. It is absolutely forbidden to blow out the contents of the pipette.
flash point → temperatura zapaljenja
Flash point is the lowest temperature at which a liquid or volatile solid gives off vapour sufficient to form an ignitable mixture with the air near the surface of the liquid or within the test vessel (NFPA).
flashback → uskakanje plamena
Flashback occurs when the flame in a gas torch burns back into the torch or hose; this is often accompanied by a hissing or squealing sound, and a pointed or smoky flame.
Citing this page:
Generalic, Eni. "Volumetric+flask." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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