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. Use the density of blood to find the mass of the blood sample. The density is given as 1.060 kg/cm³. Multiply the volume (400.00 cm³) by the density (1.060 kg/cm³) to find the mass in kilograms, then convert it to grams by multiplying by 1000.
4. Calculate the mass of lead in the blood sample using the ppm concentration. At 0.620 ppm, there are 0.620 grams of lead per 1 million grams of blood. Use the mass of the blood sample calculated in the previous step to find the mass of lead.
5. Finally, express the mass of lead in grams, ensuring that the units are consistent and the calculation reflects the concentration of lead in the given volume of blood.