Hydrogen Bonding Capacity of Water

Steps:

• Water (H₂O) has a bent structure with oxygen bonded to two hydrogens and two lone pairs on oxygen.
• Each hydrogen can donate one hydrogen bond to an oxygen lone pair on another water molecule, forming two donor bonds.
• Each oxygen lone pair can accept one hydrogen bond from a hydrogen on another water molecule, forming two acceptor bonds.
• Total maximum bonds per water molecule: 2 donors + 2 acceptors = 4.

Why D is correct:

• In liquid water's tetrahedral network, each molecule forms four hydrogen bonds, as defined by the VSEPR theory predicting oxygen's sp³ hybridization with two bonding and two lone pair orbitals.

Why the others are wrong:

• A: Insufficient; ignores multiple bonding sites.
• B: Underestimates; accounts only for donors or acceptors, not both.
• C: Incomplete; misses one acceptor site in full coordination.

Final answer: D