Search results
Results from the WOW.Com Content Network
The apparatus is heated. Dissolved gases evolve from the sample first, and the air in the capillary tube expands. Once the sample starts to boil, heating is stopped, and the temperature starts to fall. The temperature at which the liquid sample is sucked into the sealed capillary is the boiling point of the sample. [1] [2] [3] [4]
There are two conventions regarding the standard boiling point of water: The normal boiling point is commonly given as 100 °C (212 °F) (actually 99.97 °C (211.9 °F) following the thermodynamic definition of the Celsius scale based on the kelvin) at a pressure of 1 atm (101.325 kPa).
The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point or boiling point of a substance. The apparatus resembles a glass test tube with an attached handle.
Although there are few examples of such systems competitive with traditional analysis techniques, potential advantages include size/portability, speed, and cost. (micro total analysis system (μTAS) or lab-on-a-chip). Microscale chemistry reduces the amounts of chemicals used. Many developments improve the analysis of biological systems.
In physics, an ebullioscope (from Latin ēbullīre 'to boil') is an instrument for measuring the boiling point of a liquid. This can be used for determining the alcoholic strength of a mixture, or for determining the molecular weight of a non-volatile solute based on the boiling-point elevation. The procedure is known as ebullioscopy.
Ebulliometer of Świętosławski. In physics, an ebulliometer (from Latin ēbullīre 'to boil') is an instrument designed to accurately measure the boiling point of liquids by measuring the temperature of the vapor–liquid equilibrium either isobarically (at constant pressure) or isothermally (at constant temperature).
The temperature range that is determined can then be averaged to gain the melting point of the sample being examined. Apparatuses usually have a control panel that allows the starting and final temperatures, as well as the temperature gradient (in units per minute), to be programmed.
In thermodynamics, the ebullioscopic constant K b relates molality b to boiling point elevation. [1] It is the ratio of the latter to the former: = i is the van 't Hoff factor, the number of particles the solute splits into or forms when dissolved. b is the molality of the solution.