Question

Lead is an element that we humans are exposed to through food, drinking water and the environment. It is toxic to humans as it affects the central nervous system. Some symptoms that are experienced are lethargy and loss of motor coordination. A chelating agent is a compound that can form a very stable complex with a metal cation. One of these agents is dimethyl mercapto succinate acid (DMSA) which forms a stable complex with lead. The use of this compound has been suggested for treatment in patients due to lead poisoning. Determine the minimum mg of DMSA needed to complex all the Pb present in the bloodstream of a patient who has 45μg / dL in a 5.0L volume of blood. The reaction between Pb2 + and DMSAhas stoichiometry of 1: 1

Pb2+ + DMSA —————————> PbDMSA2+

Answer 1

LEAD concentration present in blood is 45ug/dl

First we have to calculate amount of pb2+ present in 5.0L of blood.

as we know 1dl of blood contain = 45 ug of pb2+

0.1L of blood contain = 45ug of pb2+

1L of blood contain = 450ug of pb2+

5L of blood contain = 2250ug of pb2+

or we can covert it in grams 5L of blood contain 0.002250g of pb2+

now pb2+ and DMSA has stoichiometry of 1:1

so, 1 mole of pb2+ react with one mole of DMSA

from this we can find how much DMSA react with 0.002250g of pb2+

0.002250/207.2 moles of pb2+ will reat with X/182.22 moles of DMSA

X=0.002250/207.2*182.22

X=0.001978g of DMSA required