Gravimetric Analysis Gravimetric Analysis Gravimetric analysis describes a set of methods in analytical chemistry for the quantitative determination of an analyte based on the mass of a solid. A simple example is the measurement of solids suspended in a water sample: A known volume of water is filtered, and the collected solids are weighed. In most cases, the analyte must first be converted to a solid by precipitation with an appropriate reagent. The precipitate can then be collected by filtration, washed, dried to remove traces of moisture from the solution, and weighed. The amount of analyte in the original sample can then be calculated from the mass of the precipitate and its chemical composition. In other cases, it may be easier to remove the analyte by vaporization. The analyte might be collected—perhaps in a cryogenic trap or on some absorbent material such as activated carbon -- and measured directly. Or, the sample can be weighed before and after it is dried; the difference between the two masses gives the mass of analyte lost. This is especially useful in determining the water content of complex materials such as foodstuffs.
Know More About :- Multiplication Properties Math.Tutorvista.com
Page No. :- 1/4
Gravimetric Analysis Definition The identification of any compound or an element can be done by using quantitative analysis or qualitative analysis. Quantitative analysis is based on the mass of a given solid while qualitative analysis is based on volume analysis. Gravimetric analysis or gravimetric determination is a method of quantitative analysis in analytical chemistry in which any element or compound gets precipitated from its solution by using suitable reagent. The precipitate obtained from the reagent can be collected by filtration. The filtrate is washed and dried to remove moisture and other impurities and weighed. The mass of the precipitate gives the amount of analyte in the original sample and its chemical composition. The unknown compound involved in quantitative analysis is called as analyte. For successful gravimetric analysis the desired substance must be completely precipitated and this precipitate must show low solubility. Gravimetric analysis also gets affected by common ion effect. The solubility of precipitate can be further decreased by decreasing the temperature of the solution by using an ice bath. The final product should have less impurity, should be filtered and dried as well so that the weight of moisture does not show any error in the final result. Thermal Gravimetric Analysis Thermogravimetric Analysis (TGA) is the technique to measure the amount and rate of change in the weight of a material as a function of temperature or time in a controlled atmosphere. By using this analysis, one can predict the thermal stability of given sample and it is used to determine the composition of given sample.
Learn More :- Graphing Parabolas Math.Tutorvista.com
Page No. :- 2/4
This technique is used for those substances which can exhibit weight loss or gain due to certain reactions like decomposition, oxidation, and dehydration. Thermogravimetric analysis gives information about the composition of multi component Systems and their thermal Stability. This technique is useful to measure the oxidative Stability of Materials and in the estimation of lifetime of a product. It shows the decomposition Kinetics of Materials and the effect of reactive or corrosive atmospheres on Materials. By using this technique, we can calculate the moisture and volatiles content of materials. The thermogravimetric analyzer consists a container which is in the form of a crucible for holding the sample, a furnace for heating the given sample at a high temperature, and an appropriate balance which can continuously monitor the sample. The modern equipment of thermogravimetric analyzer is far more sophisticated and provides much greater accuracy, precision and speed and sensitivity.
Math.Tutorvista.com
Page No. :- 4/4
Thank You For Watching
Presentation