Classify which compounds will dissolve in water and which ones will not dissolve in water.
a. Accetone
b. I-propanol
c. Hexane
d. Methanol
e. Decane
The Correct Answer and Explanation is:
To determine which compounds will dissolve in water, we need to consider their molecular properties, specifically their polarity and ability to form hydrogen bonds with water molecules. Water is a highly polar solvent, and compounds that are polar or capable of hydrogen bonding are generally soluble in water. On the other hand, nonpolar compounds are less likely to dissolve in water.
a. Acetone (C₃H₆O)
Acetone is a polar compound with a carbonyl group (C=O), which can form hydrogen bonds with water molecules. The oxygen atom in the carbonyl group is electronegative, creating a partial negative charge, while the hydrogen atoms on the surrounding carbon atoms are partially positive. This polarity allows acetone to interact with water molecules, making it highly soluble in water. Acetone will dissolve in water.
b. Isopropanol (C₃H₈O)
Isopropanol, also known as isopropyl alcohol, is a polar molecule due to the hydroxyl group (–OH) attached to a carbon chain. The oxygen in the hydroxyl group forms hydrogen bonds with water, making isopropanol soluble in water. Isopropanol will dissolve in water.
c. Hexane (C₆H₁₄)
Hexane is a nonpolar hydrocarbon with a long chain of carbon and hydrogen atoms. It does not contain any functional groups capable of hydrogen bonding or significant polarity. Due to its nonpolar nature, hexane is not able to interact effectively with polar water molecules and will not dissolve in water. Hexane will not dissolve in water.
d. Methanol (CH₃OH)
Methanol is a highly polar molecule with a hydroxyl group (–OH), similar to isopropanol, which can form hydrogen bonds with water. The small size of methanol and its ability to engage in hydrogen bonding make it highly soluble in water. Methanol will dissolve in water.
e. Decane (C₁₀H₂₂)
Decane is another nonpolar hydrocarbon with a longer carbon chain than hexane. Like hexane, decane cannot form hydrogen bonds and is not soluble in water due to the inability of nonpolar molecules to interact effectively with water molecules. Decane will not dissolve in water.
Conclusion:
- Soluble in water: Acetone, Isopropanol, Methanol
- Not soluble in water: Hexane, Decane