When lead levels in blood exceed 0.80 ppm (parts per million) the level is considered dangerous. 0.80 ppm means that 1 million g of blood would contain 0.80 g of Pb. Given that the density of blood is 1.060 kg/cm³, how many grams of Pb would be found in 400.00 mL of blood at 0.620 ppm?

• A. 0.891 g Pb
• B. 0.522 g Pb
• C. 0.263 g Pb
• D. 0.059 g Pb

Answer: (C)

Verified step by step guidance

1. First, understand the concept of ppm (parts per million). It is a way to express very dilute concentrations of substances. 1 ppm means 1 part of solute per 1 million parts of solution.
2. Convert the volume of blood from milliliters to cubic centimeters. Since 1 mL is equivalent to 1 cm³, 400.00 mL of blood is equal to 400.00 cm³.
3. Calculate the mass of the blood using its density. The density of blood is given as 1.060 kg/cm³. Use the formula: mass = density × volume. Convert the density to g/cm³ (1.060 kg/cm³ = 1060 g/cm³) and multiply by the volume in cm³.
4. Determine the mass of lead in the blood at 0.620 ppm. Since ppm is parts per million, 0.620 ppm means 0.620 g of lead per 1 million g of blood. Use the mass of blood calculated in the previous step to find the mass of lead.
5. Use the proportion: (mass of lead / mass of blood) = (0.620 / 1,000,000) to solve for the mass of lead in grams.