QUANTITATIVE ANALYSIS 447 The Molecular weight of the acid itself is clearly equal to that of the silver salt minus the atomic weight of silver plus the weight of hydrogen displaced by /G X io7'9\ the silver, i.e., to I J - 107-9 -f i. Silver acetate is one of the most soluble of the silver salts of the carboxylic acids. When determining the molecular weight of one of the aromatic acids, e.g., benzoic acid, a larger volume of water should be taken for the preparation of the silver salt, otherwise a thick cream of precipitated material is obtained and is difficult to filter and wash efficiently. For benzoic acid, therefore, add i g. of the powdered acid to about 50 ml. of water, and then add dilute ammonia until the acid has dissolved and the solution smells of ammonia. Boil and cool as before, and then dilute (if necessary) so that the solution has a volume of at least 75 ml. Precipitate the silver salt as before, filter, drain, and wash thoroughly before drying. Use 0-6-0-7 g. for the analysis.
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.