Answer to Question #254912 in General Chemistry for bensu

Question

The “normal” lead content in human blood is about 0.40 part per million (that is, 0.40 g of lead per million grams of blood). A value of 0.80 part per million (ppm) is considered to be dangerous. How many grams of lead are contained in 6.0 × 103 g of blood (the amount in an average adult) if the lead content is 0.62 ppm?

Answer 1

1⋅mg⋅L⁻¹ is called one part per million because there are

 1000×1000⋅mg =1 million milligrams in ONE LITRE of water...

So (finally!), mass of lead

=60 ppm×0.60⋅L =60⋅mg⋅L⁻¹× 0.60⋅L=36⋅mg

The lead content is 0.62/10^6. We can calculate how many grams of lead are contained in 6.0*10^3 of blood (0.006*10^6) by

multiplying (0.006*10^6)*(0.62/10^6)

= 0.00372g of lead.