Question

A vial containing 1 gram of medication has to be reconstituted to a 2.5% solution (w/v). What volume of diluent is needed and what concentration will result?

A. 25 mL, resulting in a concentration of 4 mg/L
B. 40 mL, resulting in a concentration of 2.5 mg/L
C. 40 mL, resulting in a concentration of 4 mg/mL
D. 40 mL, resulting in a concentration of 25 mg/mL

Answer 1

To achieve a 2.5% solution when reconstituting 1 gram of medication, 40 mL of diluent should be added, resulting in a final concentration of 25 mg/mL.

Step-by-step explanation:

To find the volume of diluent needed to reconstitute 1 gram of medication into a 2.5% solution (w/v), we use the formula for percent concentration: % concentration (w/v) = (mass of solute in grams / volume of solution in mL) × 100%. Given that we want a 2.5% solution, we set up the equation 2.5% = (1 g / volume of solution in mL) × 100%. Solving for the volume of solution gives us 40 mL. Thus, we need to add enough diluent to the 1 gram of medication to make up a total volume of 40 mL.

Once the solution is prepared, the concentration will be 25 mg/mL. This is because we have 1 gram, or 1000 mg, of medication in a 40 mL solution, which gives us 1000 mg / 40 mL = 25 mg/mL. Therefore, the correct answer is D. 40 mL, resulting in a concentration of 25 mg/mL.