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Gravimetric Analysis
Gravimetric methods are quantitative methods through which the amount of an analyte (the ion being analyzed) can be determined through the measurement of mass. Gravimetric analyses depend on comparing the masses of two compounds containing the analyte.
The principle behind gravimetric analysis is that the mass of an ion in a pure compound can be determined and then used to find the mass percent of the same ion in a known quantity of an impure compound. In order for the analysis to be accurate, certain conditions must be met:
- The ion being analyzed must be completely precipitated.
- The precipitate must be a pure compound.
- The precipitate must be easily filtered.
Since weight can be measured with greater accuracy than almost any other fundamental property, gravimetric analysis is potentially one of the most accurate classes of analytical methods .
Types of Gravimetric Analysis
There are 4 fundamental types of gravimetric analysis. Of which, there are 2 common types involving changes in the phase of the analyte to separate it from the rest of a mixture, resulting in a change in mass.
- Volatilization gravimetry
Volatilization Gravimetry involves separating components of our mixture by heating or chemically decomposing the sample.
- Precipitation gravimetry
Precipitation Gravimetry uses a precipitation reaction to separate one or more parts of a solution by incorporating it into a solid.
- Electrogravimetry
Electrogravimetry is a method used to separate and quantify ions of a substance, usually a metal.
- Thermogravimetric
Thermogravimetric is a method of thermal analysis in which changes in physical and chemical properties of materials are measured as a function of increasing temperature or as a function of time.
Advantages Of Gravimetric Analysis
The advantages offered by gravimetric analysis are:
(a) it is accurate and precise when using modern analytical balances;
(b) possible sources of error are readily checked, since filtrates can be tested for completeness of precipitation and precipitates may be examined for the presence of impurities;
(c) it has the important advantage of being an absolute method, i.e. one involving direct measurement without any form of calibration being required;
(d) determinations can be carried out with relatively inexpensive apparatus, the most expensive requirements being a muffle furnace and, in some cases, platinum crucibles..
Disadvantages of Gravimetric Analysis
Gravimetric analysis is lengthy and tedious as a result, only a very few gravimetric methods are currently used.
It usually provides only for the analysis of a single element, or a limited group of elements, at a time. Comparing modern dynamic flash combustion coupled with gas chromatography with traditional combustion analysis.
overall, Gravimetric analysis offers several advantages, including high accuracy, good precision, and relatively simple instrumentation. It is commonly used for the determination of various analytes, including metals, ions, and organic compounds.The accuracy and precision of gravimetric analysis depend on the careful execution of each step, including proper sample preparation, precise separation of the precipitate, thorough washing, complete drying, and accurate weighing.
The technique is widely used for the determination of various analytes, including metals, ions, and organic compounds, in different types of samples. Gravimetric analysis offers high accuracy and good precision when performed correctly and is often considered a reference method for quantitative analysis.
However, gravimetric analysis may also be a time-consuming technique compared to other analytical methods.