Question

I need to write this prediction sheet to identify an unknown You will write up a prediction sheet that lists all of the unknowns and the possible tests you could use with the expected results. HINT: Always begin with solubility Possible unknowns:

1. Pentane
2. Cyclohexene
3. 1-Pentanol
4. 2-Pentanol
5. 2-Methyl-2-Propanol
6. Pentanal Reagents or Items:

Answer 1

The solubility of a substance in a particular solvent depends on its polarity. Nonpolar substances like pentane and cyclohexene are more soluble in a nonpolar solvent such as heptane, while polar substances like alcohols (1-pentanol, 2-pentanol, and 2-methyl-2-propanol) are more soluble in water. Pentanal has both nonpolar and polar attributes, but may still be more soluble in water than in nonpolar solvents.

Step-by-step explanation:

To predict whether each of the following substances would be more soluble in water (a polar solvent) or in a hydrocarbon such as heptane (a nonpolar solvent), we need to consider the polarity of the substances relative to the solvent. Generally, "like dissolves like", which means that polar substances tend to be more soluble in polar solvents, and nonpolar substances are more soluble in nonpolar solvents.

• Pentane: Nonpolar molecule, expected to be more soluble in heptane.
• Cyclohexene: Nonpolar molecule with a double bond, also more soluble in heptane.
• 1-Pentanol and 2-Pentanol: These alcohols have polar hydroxyl groups, making them more soluble in water than in heptane.
• 2-Methyl-2-Propanol: Another alcohol, also more soluble in water due to its polar hydroxyl group.
• Pentanal: Although it has a polar carbonyl group, its long carbon chain imparts nonpolar characteristics, however, it may still be more soluble in water than other nonpolar hydrocarbons.

Understanding the solubility of various substances in different solvents is essential for many chemistry applications, including the identification of unknowns in a chemistry lab.