Which of the following substances would most likely dissolve in a nonpolar solvent?

The substance that would most likely dissolve in a nonpolar solvent is carbon tetrachloride (CCl4). Nonpolar solvents, like CCl4, have molecules that do not have significant electrical charges resulting in a lack of polarity. This characteristic allows nonpolar solutes to interact favorably with the solvent through van der Waals forces, which are weak attractions based on temporary dipoles that occur in nonpolar substances.

CCl4 itself is a nonpolar molecule due to its symmetrical tetrahedral geometry, which results in the cancellation of the dipole moments of the carbon-chlorine bonds. Hence, it is capable of dissolving other nonpolar or weakly polar substances effectively.

In contrast, sodium chloride (NaCl) and potassium bromide (KBr) are both ionic compounds that readily dissolve in polar solvents like water due to the strong interactions between the charged ions and the polar water molecules. Water (H2O) is a highly polar solvent and does not mix with nonpolar substances like CCl4. Therefore, these substances would not be suitable choices for dissolution in a nonpolar solvent.