(a) Uncertainty in formula mass. In an extremely-high-precision gravimetric titration, the uncertainty in formula mass of the primary standard could contribute to the uncertainty of the result. Review Section 3-5 and express the formula mass of potassium hydrogen phthalate, C8H5O4K, with its proper uncertainty based on a rectangular distribution of uncertainty of atomic mass.
(b) Systematic uncertainty in reagent purity. The manufacturer of potassium hydrogen phthalate states that the purity is 1.00000 ± 0.00005. In the absence of further information, we assume that the distribution of uncertainty is rectangular. What standard uncertainty would you use for the purity of this reagent?