Gravimetric analysis is a quantitative analytical technique used in chemistry to determine the amount or concentration of a particular substance in a sample. It involves the measurement of the mass of a compound or an element that is chemically related to the substance of interest.
The basic principle behind gravimetric analysis is that the mass of a pure compound can be used to determine the amount of a specific element or compound present in a sample. The technique relies on the formation of a stable and well-defined compound with the analyte (the substance being analyzed), which can be isolated and weighed.
The process typically involves several steps. First, the sample is subjected to appropriate chemical reactions to convert the analyte into a precipitate—a solid, insoluble compound. The precipitate is then collected, usually by filtration, and carefully washed to remove any impurities. After that, the collected precipitate is dried to remove any remaining moisture, and then weighed using a highly accurate balance.
By knowing the mass of the precipitate and the stoichiometry of the reaction, it is possible to calculate the amount of the analyte in the original sample. Gravimetric analysis is often used for determining the concentration of elements such as sulfate, chloride, and heavy metals in various substances, including environmental samples, pharmaceuticals, and industrial products.
Gravimetric analysis offers high precision and accuracy when performed carefully. However, it is a time-consuming technique that requires meticulous attention to detail and the use of precise equipment. Additionally, certain factors such as contamination, incomplete precipitation, or loss of the precipitate during handling can affect the accuracy of the analysis.