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The relative vapor pressures of the mixture components are important in GC Gas Chromatography but not in LC Liquid Chromatography Why is that?
Wiki User
∙ 12y ago
In Gas Chromatography, before you can correctly separate and identify the components, you need to vapourise the mixture first. How fast a substance vaporises is dependent on their vapour pressure.
In Liquid Chromatography, there is no need to vapourise the mixture and hence vapour pressure is not important here.
Wiki User
∙ 12y ago
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What is gas chromatograohy?
Gas chromatography (GC), is a common type of chromatography used in analytical chemistry for separating and analysing compounds that can bevaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture (the relative amounts of such components can also be determined). In some situations, GC may help in identifying a compound. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.
What is chalk chromatography?
In 1906, Mikhail Tswett, a Russian botanist, published a paper in which he described the separation of pigments, extracted from green leaves, by washing the mixture with petroleum ether (similar to lighter fluid) through a glass tube packed with powdered calcium carbonate (chalk). As the mixture of pigments passed down the CaCO3 -filled tube, they separated into distinctly colored zones. Tswett gave the name chromatography (the graphing of colors) to this separation technique. The method that Tswett used is known today as column chromatography. Column chromatography is a rather slow and sometimes difficult process to carry out compared with more recent developments known as paper chromatography, thin layer chromatography, gas chromatography, high pressure liquid chromatography, and ion chromatography. The method of column chromatography can be carried out in the classroom using calcium carbonate in the form of sticks of chalk. A mixture containing two or more components is deposited on a stick of chalk, a solid adsorbing substance. The components are adsorbed (i.e., held on the surface of the solid substance) to varying degrees which depend on the nature of the component, the nature of the adsorbant, and the temperature. Then the wash solvent (liquid) is added to the adsorbant and allowed to flow through it by capillary effect. As the solvent passes the deposited mixture, the components tend to be dissolved to varying extents and are swept along the solid adsorbant. The rate at which a component will move along the solid depends on its relative tendency to be dissolved in the solvent and its tendency to be adsorbed on the solid. The net effect is that, as the solvent passes slowly through the solid adsorbant, the components of the mixture -separate from each other and move along with the solvent forming rather diffuse zones or spots. With the proper choice of solvent and adsorbant, it is possible to resolve many complex mixtures into their components.
An experiment was performed in lab that was supposed to produce aspirin. How could chromatography be used to tell if aspirin was actually the product of the reaction?
i would recommend using high performance liquid chromatography or the common thin layer chromatography using a spot of the sample and a spot of dissolved aspirin to compare the Rf-value or relative retention times of the 2 spots to determine if you have aspirin
How does temperature affect chromatography?
The effect of temperature on retention characteristics in thin-layer chromatography (TLC) with low-volatility mobile phases (MP): It is shown that temperature variations in TLC in melts bring about variations in both the relative retention values and, in some cases, in the order of migration of the chromatographic zones across the layer.Hope that helped :)
Why is relative location important?
its important to know the abosulte location for climate and geograhical reasons.
What is the retardation factor?
In chemical chromatography, it is a measure of the relative mobility of components of a mixture through a stationary phase while experiencing the forces of a mobile eluent phase, based on relative intermolecular attractive forces and molecular size. In thin layer chromatography, is it the ratio of distance travelled by a component compared to the distance travelled by the eluent front from the point of contact with the mixture. In column chromatography, it is the fraction of the component in the mobile phase at equilibrium. By comparison, in gas chromatography, relative retention times on the stationary phase are measured and compared for the mixture components.
What is chromotology?
chromatology is the study of colors, and can be used in various different fields.A similar term is chromatography. It is a method of separating a solution into its constituent components by altering the speed at which different portions of the compound move through a substrate.A subset of chromatography is gas chromatography which is used to determine the relative quantities of components in a solution.
What is gas chromatograohy?
Gas chromatography (GC), is a common type of chromatography used in analytical chemistry for separating and analysing compounds that can bevaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture (the relative amounts of such components can also be determined). In some situations, GC may help in identifying a compound. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.
What is chromatograohy?
Gas chromatography (GC), is a common type of chromatography used in analytical chemistry for separating and analysing compounds that can bevaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture (the relative amounts of such components can also be determined). In some situations, GC may help in identifying a compound. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.
What is chalk chromatography?
In 1906, Mikhail Tswett, a Russian botanist, published a paper in which he described the separation of pigments, extracted from green leaves, by washing the mixture with petroleum ether (similar to lighter fluid) through a glass tube packed with powdered calcium carbonate (chalk). As the mixture of pigments passed down the CaCO3 -filled tube, they separated into distinctly colored zones. Tswett gave the name chromatography (the graphing of colors) to this separation technique. The method that Tswett used is known today as column chromatography. Column chromatography is a rather slow and sometimes difficult process to carry out compared with more recent developments known as paper chromatography, thin layer chromatography, gas chromatography, high pressure liquid chromatography, and ion chromatography. The method of column chromatography can be carried out in the classroom using calcium carbonate in the form of sticks of chalk. A mixture containing two or more components is deposited on a stick of chalk, a solid adsorbing substance. The components are adsorbed (i.e., held on the surface of the solid substance) to varying degrees which depend on the nature of the component, the nature of the adsorbant, and the temperature. Then the wash solvent (liquid) is added to the adsorbant and allowed to flow through it by capillary effect. As the solvent passes the deposited mixture, the components tend to be dissolved to varying extents and are swept along the solid adsorbant. The rate at which a component will move along the solid depends on its relative tendency to be dissolved in the solvent and its tendency to be adsorbed on the solid. The net effect is that, as the solvent passes slowly through the solid adsorbant, the components of the mixture -separate from each other and move along with the solvent forming rather diffuse zones or spots. With the proper choice of solvent and adsorbant, it is possible to resolve many complex mixtures into their components.
What is a component bar chart?
This is used to represent the relative size of the components.
Select the three components of the relative value unit.?
malpractice2) work3) overhead
What is a percentage component bar chart?
This is used to represent the relative size of the components.
What is allometry?
Anisometric growth in which that results when two components have different relative growth rates.
What are the three components of the relative value unit?
Physician work, Practice expense, and Malpractice
Why is relative and absolute location important?
Absolute Location and Relative Location is important it is because it telling you EXACTLY the location it is at.
An experiment was performed in lab that was supposed to produce aspirin. How could chromatography be used to tell if aspirin was actually the product of the reaction?
i would recommend using high performance liquid chromatography or the common thin layer chromatography using a spot of the sample and a spot of dissolved aspirin to compare the Rf-value or relative retention times of the 2 spots to determine if you have aspirin
