Question

A pharmacy technician has been given 100 milliliters of a 25% solution and been asked to dilute the solution to 500 milliliters with sterile water. she has also been asked to label the solution. what percentage should appear on the label?

Answer 1

Percentage by volume is the amount of a component in a mixture per 100 units of volume of the total mixture. To solve this we use the equation,

M1V1 = M2V2

where M1 is the concentration of the stock solution, V1 is the volume of the stock solution, M2 is the concentration of the new solution and V2 is its volume.

25% x 100 = M2 x 500

M2 = 5%

The new label should be 5%.