Welcome to the Chemistry Forensics Agency. At the CFA, we use our chemistry expertise

and understanding to help solve problems of a potentially criminal nature.

Bucks McGee, after being poisoned, is currently being treated in the hospital with an

antidote$-$ the chemical Fe$7($CN$)18.$ The compound is so intensely coloured that even a small

amount of it makes for a black or dark blue suspension.

Given that this antidote has never been administered at the hospital, none of the doctors

or nurses have experience with it$.$ There is one very old bottle of Fe$7($CN$)18$ pills in the

medicine storeroom, but the label is worn, and the units are in the old, archaic British

Apothecaries$$ system which has unusual units like drachms, scruples, grains, and mites:

$453\mathrm{.}6$ grams $($g$)$

$=1$ pound $($lb$)$

$=12$ ounces $()$

$=96$ drachms $()$

$=288$ scruples $()$

$=5760$ grains $($gr$)$

$=115200$ mites $($m$)$

It would take days $($at least!$)$ for a new bottle of the antidote to be ordered and received,

and Bucks McGee probably doesn$$t have days!

The instructions on the worn bottle label of Fe$7($CN$)18$ pills read as follows:

$$Each pi$-$l c$-$ntains $12\mathrm{.}5--$ of act$-$ve $-$ngre$-$dient. Adm$$i$--$ister thr$-$e tim$-$s $-$aily unt$-$l $-$ymptoms dimi$-$ish.$$

One doctor phoned an old, retired physician who had used this antidote long ago at

another hospital, and who seemed to remember that they used to make $0\mathrm{.}025$ M solutions

of this compound in ethanol and give $45$ mL of the solution three times daily.

What critical information is missing from the worn label? How many pills

should the patient be given each day to remove the poison? Please work quickly!

Instructions:

Write a professional report to communicate your results for the administration of the

antidote.

$$ What should the label say? What unit is missing $($This has to be one of the units listed in the background information$)?$ Explain how you came to your

conclusion.

$$ How many pills should be given $3$ times daily? Show your work below, including all

relevant unit conversions.