A nurse is preparing to administer valproic acid 125 mg PO. Available is valproic acid syrup 250 mg/5 mL. How many mL should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

Desired dose = 125 mg. Available concentration = 250 mg/5 mL. Find the concentration in mg per mL: Concentration (mg/mL) = 250 mg / 5 mL = 50 mg/mL. Calculate the volume to administer in milliliters (mL). Volume (mL) = Desired dose (mg) / Concentration (mg/mL) = 125 mg / 50 mg/mL = 2.5 mL.