You need to make a solution of Ca(NO3)2 for a class demonstration. First, you measure a quantity of the solid Ca(NO3)2 by weighing the reagent container before obtaining the sample (4.2540 ± 0.0003 g) and after taking some reagent (3.9440 ± 0.0003 g). You were about to transfer the Ca(NO3)2 into a 100- ml volumetric flask, but notice that you forgot to wash it the previous week and there is something green growing in it. So rather than cleaning the volumetric flask, you instead decide to just use a beaker and fill it to a final volume of 0.100 ± 0.005 L. The molar mass of Ca(NO3)2 is 164.10 g/mol, and its uncertainty is negligible (i.e. treat it as a constant).
a. Calculate the concentration of nitrate ions in the resulting solution (don't forget about the stoichiometry), and determine the uncertainty in that value. What is the primary contribution to the uncertainty?
b. A typical 100-ml volumetric flask has an uncertainty of ± 0.12 ml. If you had made the above solution in a volumetric flask instead of the beaker, what would have been the resulting concentration and uncertainty?