Final answer:
The solubility of a substance in a solvent depends on the polarity of both the solute and the solvent. Nonpolar substances like iodine and cyclohexane dissolve better in nonpolar solvents like carbon tetrachloride and benzene. Polar substances like methanol and sodium sulfate are more soluble in polar solvents such as water.
Step-by-step explanation:
To predict whether a substance will be more soluble in water (a polar solvent) or in a hydrocarbon like heptane (a nonpolar solvent), you must consider the polarity of the substance in question. A general rule of solubility is "like dissolves like," meaning that polar substances tend to dissolve in polar solvents, while nonpolar substances are more soluble in nonpolar solvents.
Example 6.4.2: Polar and Nonpolar Solvents
Considering iodine (I2), it would be more soluble in carbon tetrachloride (CCl4), a nonpolar solvent, rather than water (H2O), because iodine is a nonpolar substance.
Exercise 6.4.3: Solubility in Toluene
Toluene (C6H5-CH3) is nonpolar, so it will dissolve substances like octane (C8H18), which is also nonpolar. It is not effective for dissolving polar substances such as water (H2O) or sodium sulfate (Na2SO4).
Water as a Polar Solvent
Since water is a polar solvent, it will dissolve polar substances like methanol (CH3OH) and sodium sulfate (Na2SO4). Nonpolar substances like octane (C8H18) are not soluble in water.
Exercise 14.2.1: Solubility in Benzene
Benzene is a nonpolar solvent, which means that cyclohexane, being nonpolar, will be most soluble in it. Polar substances like ammonium chloride and ethylene glycol (HOCH2CH2OH) will be least soluble in benzene.