Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). 4.5 g of sodium chloride is dissolved in water to a total volume of 1000 mL. What is the percentage strength p (% w/v)?

Practice exercise (made-up values, not clinical guidance). A solution of potassium permanganate has a ratio strength of 1:5 000. How many milligrams m are in 500 mL?

Practice exercise (made-up values, not clinical guidance). A vial contains ampicillin 1000 mg as a powder. The practice label says to add 3.5 mL of sterile water; the powder adds 0.5 mL to the volume. What is the concentration C in mg/mL after reconstitution?

Practice exercise (made-up values, not clinical guidance). A vial contains ceftriaxone 1000 mg as a powder. The practice label says to add 9.6 mL of sterile water; the powder adds 0.4 mL to the volume. The prescribed dose is 250 mg. What volume V do you draw up? Round to one decimal place.

Practice exercise (made-up values, not clinical guidance). You have 120 g of 5% coal tar ointment. How many grams m of 1% coal tar ointment must you add to make a 2% ointment? Round to the nearest whole gram.

Practice exercise (made-up values, not clinical guidance). You have 40 g of 5% coal tar ointment. How many grams m of 1% coal tar ointment must you add to make a 3% ointment? Round to the nearest whole gram.