(6) Terpin hydrate, an expectorant, is soluble in alcohol (40% or higher) but
is insoluble in water. Should the alcohol concentration fall below 40%, the terpin
hydrate will precipitate out of solution. Codeine sulfate is soluble in water but only
slightly soluble in alcohol. Terpin hydrate and codeine sulfate are frequently used in
combination in cough preparations. In order to allow both medications to remain in
solution, the alcohol concentration must be 40% and 50%. How many milliliters of high
alcoholic elixir (75%) and how many milliliters of low alcoholic elixir (10%) must be
combined to make one gallon of 45% alcoholic elixir to be used as a vehicle for the two
ANS: ___________ml 75%
(7) How many milliliters of normal saline (diluent) must be added to one fluid
ounce of 1-percent phenylephrine HCl solution to reduce the strength to 1/4%?
ANS: ___________ ml normal saline
(8) How many milliliters of distilled water must be added to one liter of a
1:200 solution of potassium permanganate (KMnO4) to make it a 1:4000 solution?
ANS: ___________ ml distilled water