Principle and steps involved in the gravimetric analysis
Gravimetric analysis is a quantitative analytical method that involves the determination of the mass of a substance by its chemical conversion to a compound of known composition. The principle involved in gravimetric analysis is based on the law of conservation of mass, which states that mass is neither created nor destroyed during a chemical reaction.
Gravimetric analysis involves the following steps:
- Sample preparation: The sample is first collected and prepared for analysis. The sample should be representative of the entire sample population and should be homogenous.
- Precipitation: The analyte is converted into a solid precipitate by adding a reagent that forms a sparingly soluble compound with the analyte. The precipitate should be pure and of known composition.
- Filtration: The precipitate is separated from the solution by filtration. The filter paper used should be of known weight and should not react with the precipitate.
- Washing: The precipitate is washed with a suitable solvent to remove any impurities that may have adsorbed on its surface.
- Drying: The precipitate is dried in an oven to remove any remaining water molecules.
- Weighing: The dried precipitate is weighed on a balance to determine its mass.
- Calculation: The mass of the analyte is calculated from the mass of the precipitate and the stoichiometry of the reaction.
Gravimetric analysis is a precise and accurate method for determining the amount of an analyte in a sample. However, it requires careful sample preparation and handling to minimize errors. The method is widely used in various fields, including pharmaceuticals, environmental monitoring, and materials science.
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