Final answer:
Vegetable oil, a nonpolar substance, will be more soluble in heptane. Isopropyl alcohol and potassium bromide, which are polar and ionic respectively, will be more soluble in water due to their polar interactions.
Step-by-step explanation:
To predict whether each substance would be more soluble in water (polar solvent) or in a hydrocarbon such as heptane (C7H16, nonpolar solvent), we apply the principle 'like dissolves like':
- (a) Vegetable oil: As a nonpolar substance, vegetable oil is more soluble in nonpolar solvents. It will therefore be more soluble in a hydrocarbon such as heptane than in polar water.
- (b) Isopropyl alcohol: Being a polar molecule due to its hydroxyl (-OH) group, isopropyl alcohol has affinity for other polar molecules. It is more soluble in water.
- (c) Potassium bromide: KBr is an ionic compound and is expected to be soluble in polar solvents like water because of the strong ionic interactions with the polar water molecules. Potassium bromide will be more soluble in water.
According to this prediction, we see solubility is strongly influenced by the polarity of the solute and the solvent.