Gravimetriás

Gravimetriás is a term derived from the Greek words "gravitas" meaning weight and "metron" meaning measure. It refers to a class of analytical techniques used in chemistry and geology to determine the amount of a substance by measuring its weight. Essentially, gravimetric analysis involves isolating the substance of interest in a pure form, either as a precipitate or a volatile product, and then accurately weighing it.

There are two primary methods within gravimetric analysis: precipitation and volatilization. In precipitation gravimetry, the analyte is converted into an insoluble solid (precipitate) by adding a suitable reagent. This precipitate is then filtered, washed, dried, and weighed. The mass of the precipitate is then used to calculate the amount of the original analyte. In volatilization gravimetry, the analyte is separated by converting it into a gaseous product, which is then removed by heating or other means. The remaining residue is weighed, or the difference in weight before and after volatilization is measured.

Gravimetric methods are known for their high accuracy and precision, provided that careful technique is employed. They are often used as reference methods for calibrating other analytical instruments or for determining the composition of standards. While generally slower than other analytical techniques, gravimetry remains a valuable tool in various fields, including environmental monitoring, pharmaceutical analysis, and material science, where absolute accuracy is paramount.