Answer
Of the given liquids, diiodomethane will serve the purpose of separating the desired granular material from the undesired granular material.
Work Step by Step
Want to separate desired granular material with a density of 3.62 g/cm^3 from an undesired granular material with a density of 2.04 g/cm^3.
You will need to find a substance with a density in between 2.04 g/cm^3 and 3.62 g/cm^3.
2.04 is the minimum density and 3.62 is the maximum density possible for your liquid.
Densities:
carbon tetrachloride: 1.59 g/cm^3
1.59 < 2.04 (does not work)
hexane: 0.66 g/cm^3
0.66 < 2.04 (does not work)
benzene: 0.88 g/cm^3
0.88 < 2.04 (does not work)
diiodomethane: 3.32 g/cm^3
2.04 < 3.32 < 3.62 (does work)
Of the given liquids, diiodomethane will serve the purpose of separating the desired granular material from the undesired granular material.