Answer:
20ppm
Step-by-step explanation:
parts per million are defined as the mass of solute in mg (In this case, mass of DDT) per kg of sample.
To solve this question we must find the mass of DDT in mg and the mass of sample in kg:
Mass DDT:
0.10g * (1000mg / 1g) = 100mg
Mass sample:
5000g * (1kg / 1000g) = 5kg
Parts per Million:
100mg / 5kg =
20ppm