A patient requires 20 mEq of potassium chloride. If the stock solution contains 10 mEq in 5 mL, how many mL are needed?

To determine how many milliliters of the potassium chloride stock solution are needed for a patient requiring 20 mEq, it is essential to understand the concentration of the solution provided. The stock solution offers 10 mEq of potassium chloride in 5 mL. This means that for every 5 mL of the solution, there are 10 mEq available.

To find out how many milliliters are necessary to obtain 20 mEq, it can be useful to set up a proportion based on the available concentration. Since 10 mEq is contained in 5 mL, to achieve 20 mEq, which is double the amount, you simply need double the volume. Thus:

If 10 mEq = 5 mL

Then 20 mEq = 10 mL

Therefore, the correct amount needed from the stock solution to administer to the patient to achieve the required dosage of 20 mEq of potassium chloride is 10 mL. This makes the correct choice clear.