linked - Investigating the Terror

(123 pounds) of urea nitrate. If nitric acid was the limiting reagent, for
every 63 grams (63 pounds) of nitric acid that was missing, the
perpetrators potentially could have produced 123 grams (123 pounds) of
urea nitrate.
One additional factor must be taken into consideration: the purity of the
components. The calculations above assumed that the components were
100% pure. If, for example, the urea was only 50% pure, you would need
twice as many grams (or pounds) of urea as indicated above: 120 grams
(or 120 pounds) would be needed for every 63 grams (63 pounds) of
100% pure nitric acid. Similarly, if both components were less than 100%
pure, appropriate adjustments would have to be made.
b. Factual Background: Jourdan's Calculations
On March 7 or 8, 1993, Williams provided a list of the missing
components to a forensic chemist in the CTU (Thomas Jourdan) and
asked him to calculate the potential amount of urea nitrate that could
have been produced. Jourdan made the calculations and reported back to
Williams, Agent Richard Hahn, and possibly EU Chief J. Christopher
Ronay. It appeared to Jourdan that they did not understand his
explanation of how nitric acid was the limiting reagent, so Jourdan
prepared a memorandum explaining his calculations and gave it to
Ronay and Williams and probably to Hahn.
Based on the figures Jourdan had, he determined that the nitric acid was
the limiting reagent, and determined that the upper limit was the
production of 1821 pounds of urea nitrate. Jourdan used a 97% yield
instead of 100% because a staff member (this was James Molnar, see
p.85, supra) had achieved such a yield in the Laboratory. Jourdan also
noted that [r]ecovered empty bottles of HNO3 [nitric acid] indicated
usage of about equal portions of 70.4% (reagent grade) nitric acid and
67% (technical grade) nitric acid. He defined limiting reagent as
stoichiometrically you run out of it first, and stated that ordinarily, urea is
the limiting reagent to make sure the urea nitrate is not adulterated with
unreacted urea, which would inhibit the explosive's effectiveness.
At the time Williams testified at the Salameh trial, his figures regarding
the missing components were different (presumably updated) from the
ones given to Jourdan. At the time of the trial it was determined that 1200