If a patient requires 500 mg of a medication but is only given a concentration of 100 mg per mL, how many mL do you need to administer?

To determine the volume of medication to administer, divide the total required dose by the concentration of the medication. In this case, the patient needs 500 mg of the medication, and the concentration available is 100 mg per mL.

Using the formula:

Volume (mL) = Total Dose (mg) / Concentration (mg/mL)

The calculation would be:

Volume (mL) = 500 mg / 100 mg/mL = 5 mL.

This shows that to achieve the required dosage of 500 mg, you would need to administer 5 mL of the medication at a concentration of 100 mg per mL. This matches the correct answer, making it the appropriate choice for this question.