A nurse is preparing to administer procaine penicillin G 50,000 units/kg IM once daily to a child who weighs 55 lb. The amount available is procaine penicillin G injection 600,000 units/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.)

Step-by-step calculation: The child's weight is 55 lb. The medication dosage is 50,000 units/kg. The available medication concentration is 600,000 units/mL. Calculating the total dose in units: Convert the child's weight to kg: 55 lb ÷ 2.2 lb/kg = 25 kg Calculate the total dose: 25 kg × 50,000 units/kg = 1,250,000 units Calculating the volume to administer: Use the concentration of the medication: 1,250,000 units ÷ 600,000 units/mL = 2.0833 mL Rounding the answer: 2.0833 rounds to 2.1 mL