Which of the following statements helps to explain why water molecules form hydrogen bonds?

• A. Water molecules contain carbon atoms, which are essential for hydrogen bonding.
• B. Water molecules have a high molecular weight, which facilitates hydrogen bonding.
• C. Water molecules are nonpolar, which allows them to form hydrogen bonds.
• D. Water molecules have a bent shape, leading to a polar molecule.

Answer: (D)

Verified step by step guidance

1. Understand the concept of hydrogen bonding: Hydrogen bonds are a type of weak chemical bond that occurs when a hydrogen atom, which is covalently bonded to a more electronegative atom, interacts with another electronegative atom nearby.
2. Identify the key characteristics of water molecules: Water (H₂O) consists of two hydrogen atoms covalently bonded to one oxygen atom. The oxygen atom is more electronegative than hydrogen, creating a polar covalent bond.
3. Recognize the molecular geometry of water: Water molecules have a bent shape due to the two lone pairs of electrons on the oxygen atom. This shape contributes to the polarity of the molecule.
4. Explain the polarity of water: The bent shape and the difference in electronegativity between oxygen and hydrogen result in a partial negative charge near the oxygen and a partial positive charge near the hydrogen atoms, making water a polar molecule.
5. Connect polarity to hydrogen bonding: The polarity of water molecules allows them to form hydrogen bonds, as the partially positive hydrogen atoms can attract the partially negative oxygen atoms of nearby water molecules.