Final answer:
Glucose and ethanol are the most soluble in water due to their polar nature and capability to form hydrogen bonds with water, while potassium chloride is also soluble due to its ionic nature.
Step-by-step explanation:
Glucose and ethanol exhibit high solubility in water due to their ability to form hydrogen bonds with the polar solvent. Glucose, a sugar with a molecular formula of C6H12O6, possesses numerous hydroxyl (OH) groups. These hydroxyl groups readily engage in hydrogen bonding with water molecules, enhancing its solubility. Similarly, ethanol (C2H5OH) contains an OH group, allowing it to form hydrogen bonds with water and dissolve effectively.
On the other hand, potassium chloride (KCl) is an ionic compound that dissolves in water through ion release rather than hydrogen bonding. While KCl is soluble, its mechanism of dissolution involves the separation of ions in the aqueous solution.
In contrast, octanol (C8H17OH) has a hydrocarbon chain that is more extended than ethanol's, reducing its solubility in water. The prolonged hydrocarbon section diminishes the impact of the OH group, making octanol less prone to form hydrogen bonds with water molecules, resulting in lower solubility compared to ethanol and glucose.