Purity of the precipitate: post-precipitation in Gravimetric analysis
In gravimetric analysis, the purity of the precipitate is a critical factor that affects the accuracy and precision of the analysis. The purity of the precipitate can be assessed by conducting a post-precipitation analysis.
After the precipitation and filtration steps, the collected precipitate is washed and dried to remove any impurities that may have adsorbed onto its surface. The dried precipitate is then weighed on an analytical balance to determine its mass.
To assess the purity of the precipitate, the mass of the precipitate is compared to the theoretical mass that would be obtained if the precipitate were pure. The theoretical mass can be calculated based on the stoichiometry of the reaction and the amount of the reactants used.
If the mass of the precipitate is less than the theoretical mass, it indicates that the precipitate is impure and that some of the analyte may have been lost during the process. In this case, the analysis should be repeated with a larger sample size or with more careful precipitation and filtration techniques.
If the mass of the precipitate is greater than the theoretical mass, it may indicate that some impurities are still present in the precipitate. In this case, the precipitate may need to be washed more thoroughly or re-precipitated to remove any remaining impurities.
Overall, the assessment of the purity of the precipitate is essential to ensure accurate and reliable results in gravimetric analysis. It is important to use high-quality reagents and careful laboratory techniques to minimize the potential for impurities and to conduct post-precipitation analysis to verify the purity of the precipitate.
First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise
Suggested readings:
