Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: DUDE778 on February 11, 2008, 10:56:44 PM

Sometimes, when repeated assays are to be performed, the sample size is standardized and chosen such that the ultimately measured quantity is numerically equivalent to some other desired proportionate quantity.
Suppose the sulfur content of a mineral sample is determined by complete conversion to Ag2S(s).
What mass of sample must be chosen, so that the number of grams of Ag2S(s) obtained is equal to one eighth of the percent sulfur in the sample?

Calculate the percent composition of sulfur in the Ag_{2}S; and, then take 0.125% of that value.
Use these links to do your calculations:
http://ghs.gresham.k12.or.us/science/elsberry/Lecture%20Notes%20the%20Mole%20&%20Stoichiometry.pdf
http://www.chem.tamu.edu/class/majors/tutorialnotefiles/percentcomp.htm