In which solvent would cyclohexane have the lowest solubility: 1-pentanol, diethyl ether, ethanol, or hexane?

Verified step by step guidance

1. Identify the polarity of cyclohexane. Cyclohexane is a nonpolar molecule because it consists only of carbon and hydrogen atoms arranged in a symmetrical ring structure, resulting in no significant dipole moment.
2. Recall the principle of 'like dissolves like,' which states that polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes. This principle will guide us in determining solubility.
3. Analyze the polarity of each solvent: (1) 1-pentanol is a polar molecule due to its hydroxyl (-OH) group, (2) diethyl ether is slightly polar because of the oxygen atom, (3) ethanol is polar due to its hydroxyl (-OH) group, and (4) hexane is nonpolar because it is a hydrocarbon similar to cyclohexane.
4. Compare the polarity of cyclohexane with each solvent. Cyclohexane will have the lowest solubility in the most polar solvent because it is nonpolar and does not interact well with polar solvents.
5. Determine which solvent is the most polar among the options. Ethanol, with its small size and hydroxyl group, is the most polar solvent listed. Therefore, cyclohexane will have the lowest solubility in ethanol.

Key Concepts

Polarity of Solvents

Solvents can be classified as polar or nonpolar based on their molecular structure and the distribution of electrical charge. Polar solvents, like ethanol, have significant dipole moments due to their electronegative atoms, while nonpolar solvents, such as cyclohexane and hexane, have even charge distribution. The principle 'like dissolves like' suggests that nonpolar solutes are more soluble in nonpolar solvents.

Hydrogen Bonding

Hydrogen bonding is a strong type of dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like oxygen or nitrogen. In the context of solubility, solvents capable of hydrogen bonding, such as 1-pentanol and ethanol, can interact more favorably with polar solutes, while nonpolar solutes like cyclohexane do not engage in hydrogen bonding, affecting their solubility.

Solubility Principles

Solubility is influenced by the nature of the solute and solvent, temperature, and pressure. For nonpolar solutes like cyclohexane, solubility is generally higher in nonpolar solvents. Therefore, when comparing the solubility of cyclohexane in the given solvents, it is expected to be least soluble in the most polar solvent, which in this case is ethanol.