Which of the following best determines whether a molecule is soluble or insoluble in water?

• A. The molecular mass of the molecule
• B. The color of the molecule
• C. The boiling point of the molecule
• D. The polarity of the molecule and its ability to form hydrogen bonds with water

Answer: (D)

Verified step by step guidance

1. Understand that solubility in water largely depends on the interactions between the molecule and water molecules.
2. Recall that water is a polar solvent, so molecules that are polar or can form hydrogen bonds tend to dissolve well in water.
3. Recognize that molecular mass, color, and boiling point do not directly determine solubility in water, although they may influence other physical properties.
4. Focus on the concept of polarity: polar molecules have uneven charge distribution, which allows them to interact favorably with water's polar molecules.
5. Consider hydrogen bonding: molecules capable of forming hydrogen bonds with water (such as those containing -OH, -NH, or -FH groups) are generally more soluble in water.