Pharmacy calculations worksheet with answers

A solution is 5% w/v. You need 130 mg of the drug. Draw up the volume in the syringe: what volume V is that?

Practice exercise (made-up values, not clinical guidance). 40 g of glycerin is dissolved in water to a total volume of 200 mL. What is the percentage strength p (% w/v)?

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?

A solution has a ratio strength of 1:1000. You need 0.28 mg. Draw up the volume in the 1 mL syringe: what volume V is that?

A vial holds 250 mg of powder. You add 1.7 mL of diluent, and the powder adds 0.8 mL of volume. The prescription is 170 mg. Draw up the dose: what volume V do you give?

Practice exercise (made-up values, not clinical guidance). You must prepare 300 mL of 5% sodium chloride by mixing 23% and 3% sodium chloride. How many mL V of the 23% solution do you need? Round to the nearest whole mL.