Final answer:
To convert and administer the correct dosage of morphine, calculate that 1/8 grain equals 8.1 mg, and with a 2 mg/mL supply, administer 4.05 mL per dose.
Step-by-step explanation:
The question involves calculating the correct dosage of morphine to be administered intravenously and requires a conversion from grains to milligrams, and then from milligrams to milliliters, using the supply concentration. Firstly, we must establish that 1 grain equals 64.8 milligrams. Thus, 1/8 grain of morphine is equivalent to 64.8 mg ÷ 8 = 8.1 mg. The supply provided is 2 mg/mL, so the necessary volume to deliver 8.1 mg of morphine is 8.1 mg ÷ 2 mg/mL = 4.05 mL. Therefore, you will administer 4.05 mL per dose.