Why do polar molecules interact with water?
A They have carbon atoms
B They are hydrophobic
C They are also partially charged
D They don’t like water
The correct answer and explanation is:
The correct answer is C) They are also partially charged.
Polar molecules interact with water because they have regions of partial positive and partial negative charges, which allows them to form hydrogen bonds with water molecules. Water is a polar solvent, meaning it also has partial positive (hydrogen atoms) and partial negative (oxygen atom) charges. These oppositely charged regions of water molecules are attracted to the charges on the polar molecules.
The polarity of a molecule arises from its molecular structure, where the distribution of electrons is uneven, resulting in regions of partial positive and negative charges. For example, in water (H2O), the oxygen atom is more electronegative than the hydrogen atoms, pulling the shared electrons closer to itself and leaving the hydrogen atoms slightly positive. This creates a dipole moment in the water molecule. When a polar molecule, such as an alcohol or sugar, is introduced to water, the partially positive regions of the water molecules are attracted to the negative parts of the polar molecule, and the partially negative regions of the water molecules are attracted to the positive parts of the polar molecule.
This attraction allows polar molecules to dissolve or interact well with water, as the molecules can form a stable solution through these intermolecular forces. The formation of hydrogen bonds between water and polar molecules is key in many biological processes and the solubility of substances in water.
On the other hand, nonpolar or hydrophobic molecules, such as oils, do not interact well with water because they do not have partial charges that can form hydrogen bonds with water molecules. Instead, nonpolar molecules tend to cluster together and avoid water.