Solute Which Is The Better Solvent? I CH3(CH2)4CH3 H C H C C H2O I C H H Ui C
The correct answer and explanation is:
The better solvent between n-hexane (CH₃(CH₂)₄CH₃) and water (H₂O) depends on the type of solute and the nature of the interaction required for dissolution.
Correct Answer:
Water (H₂O) is the better solvent in general, especially for polar and ionic compounds, due to its polar nature and hydrogen bonding capabilities.
Explanation:
1. Nature of Solvent:
- n-Hexane: A nonpolar solvent with a linear alkane structure. It dissolves nonpolar substances effectively due to dispersion forces. Examples include oils, fats, and other hydrophobic molecules.
- Water: A highly polar solvent with a bent molecular geometry, giving it a strong dipole moment. Water forms hydrogen bonds, enabling it to dissolve ionic and polar substances, such as salts and sugars.
2. Polarity: Water is polar, with partial positive (δ⁺) charges on the hydrogen atoms and partial negative (δ⁻) charges on the oxygen atom. This makes it highly effective at stabilizing charged or polar solutes. n-Hexane, being nonpolar, cannot interact with polar solutes and thus fails to dissolve them.
3. Hydrogen Bonding: Water forms hydrogen bonds, which allow it to interact with solutes that have polar functional groups (e.g., -OH, -COOH). This property is absent in n-hexane, limiting its solvent capabilities to nonpolar solutes.
4. Solubility Rule: The principle of “like dissolves like” explains why water is superior for polar solutes and n-hexane for nonpolar solutes. Polar solvents dissolve polar/ionic solutes, while nonpolar solvents dissolve nonpolar solutes.
5. Versatility: Water’s high dielectric constant makes it capable of weakening ionic bonds, enhancing solubility for salts and electrolytes. n-Hexane lacks this property and is primarily used for hydrophobic compounds.
In summary, water is the better solvent for a wide range of compounds due to its polarity, hydrogen bonding, and dielectric properties, whereas n-hexane is limited to nonpolar solutes.