Gravimetry
Introduction
Gravimentry is the quaantitative measurement of an analyte by weighing a pure, solid form of the analyte. Since gravimentric analysis is an absolute measurement, it is the principal method for analyzing and preparing primary standards. A typical experimental procedure to determine an unknown concentration of an analyte in solution is an follows:
-quantitatively precipitate the analyte from solution
-collect the precipitate by filtering and wash it to remove impurities
-dry the solid in an oven to remove solvent
-weigh the solid on an analytical balance
-calculate the analyte concentration in the original solution based on the weight of the precipitate
Examples of Gravimetric Lab Procedures
Gravimetric Determination of Iron
1. Determine constans weight of the crucibler
2. Oxidation of iron sample
3. Precipitation of iron hydroxide
4. Ignition of iron hydroxide to iron oxide
5. Determine constant weight to the cruciblest plus iron oxide
6. Calculation of iron the sample