An extra-strength aspirin contains 0.500 g of aspirin. How many grains is this? (1 grain = 64.8 mg)

• A. 32.4 grains
• B. 7.72 grains
• C. 0.0077 grains
• D. 12.5 grains

Answer: (B)

Verified step by step guidance

1. Identify the given information: the mass of aspirin is 0.500 g, and the conversion factor is 1 grain = 64.8 mg.
2. Convert the mass of aspirin from grams to milligrams because the conversion factor is given in milligrams. Use the relationship: \(\text{mass in mg} = \text{mass in g} \times 1000\).
3. Set up the conversion from milligrams to grains using the conversion factor: \(\text{mass in grains} = \frac{\text{mass in mg}}{64.8}\).
4. Substitute the value of the mass in milligrams into the conversion equation to find the mass in grains.
5. Perform the division to calculate the number of grains corresponding to 0.500 g of aspirin.