Lipitor, a pharmaceutical drug that has been shown to lower 'bad' cholesterol levels, while boosting 'good' cholesterol levels had over \$12 billion in sales last year. Each pill weighs 2.5 g, which contains 4.0% of the active ingredient by mass. What mass in kg of the active ingredient is present in one bottle of 120 pills?

• A. 0.112 kg
• B. 0.020 kg
• C. 0.012 kg
• D. 0.024 kg
• E. 1.02 kg

Answer: (C)

Verified step by step guidance

1. Determine the mass of the active ingredient in one pill by using the percentage by mass. The formula to use is: \( \text{mass of active ingredient in one pill} = \text{mass of one pill} \times \frac{\text{percentage of active ingredient}}{100} \).
2. Substitute the given values into the formula: \( \text{mass of active ingredient in one pill} = 2.5 \text{ g} \times \frac{4.0}{100} \).
3. Calculate the mass of the active ingredient in one pill using the above expression.
4. Multiply the mass of the active ingredient in one pill by the number of pills in the bottle to find the total mass of the active ingredient: \( \text{total mass of active ingredient} = \text{mass of active ingredient in one pill} \times 120 \).
5. Convert the total mass of the active ingredient from grams to kilograms by dividing by 1000: \( \text{mass in kg} = \frac{\text{total mass in g}}{1000} \).