A solution contains 2 meq/ml of kcl. if a 20 ml ampule of this solution is diluted to 1 liter what is the percent strength of the resulting solution

We are given that the concentration of the KCl is 2 meq / mL. Assuming that the ampule also has exactly this concentration, therefore:

amount of KCl in ampule = (2 meq / mL) * (20 mL)

amount of KCl in ampule = 40 meq

This amount of KCl is now inside a solution of 1 Liter (also equivalent to 1000 mL), therefore the new concentration in the resulting solution is:

new concentration = 40 meq / 1000 mL

new concentration = 0.04 meq / mL

Since 0.04 in decimal is 4% in percentage, therefore the strength of the resulting solution is 4% KCl.