What formula would you use to calculate the volume needed for a percent solution?

To calculate the volume needed for a percent solution, the first step is to understand the relationship between the concentrations of the solution you have (the have percentage) and the concentration you desire (the want percentage). The correct formula effectively sets up a proportion that allows you to convert the total volume you need based on the desired concentration.

The formula states that the volume needed divided by the concentration you have is equal to the volume prescribed divided by the concentration you want. This relationship allows you to determine how much of the solution you must use in order to achieve the target concentration based on how concentrated your stock solution is. When rearranged, this formula can help solve for the unknown volume in various scenarios, making it a versatile tool in pharmacy calculations.

In this case, the choice presented incorporates the essential elements of concentration and volume, creating a proportion that is used frequently in pharmacy practice to mix or dilute solutions accurately. It is foundational in ensuring that patients receive the correct dosage for their treatment. This principle is essential in compounding pharmaceuticals, where precise calculations matter significantly for patient safety and effectiveness of therapy.