Which types of intermolecular forces are expected to exist between PO(OH)3 molecules?

• A. Only London dispersion forces
• B. Only dipole-dipole interactions
• C. Hydrogen bonding, dipole-dipole interactions, and London dispersion forces
• D. Ionic bonding and London dispersion forces

Answer: (C)

Verified step by step guidance

1. Identify the molecular structure of PO(OH)3, which is phosphorous acid. It contains P=O and P–OH groups, where the OH groups have hydrogen atoms bonded to highly electronegative oxygen atoms.
2. Recognize that the presence of O–H bonds allows for hydrogen bonding because hydrogen is directly bonded to oxygen, a highly electronegative atom, enabling strong intermolecular attractions.
3. Note that the molecule is polar due to differences in electronegativity between P, O, and H atoms, so dipole-dipole interactions will also be present between the polar molecules.
4. Remember that all molecules, regardless of polarity, exhibit London dispersion forces (induced dipole-induced dipole interactions) due to temporary fluctuations in electron density.
5. Conclude that the intermolecular forces present in PO(OH)3 molecules include hydrogen bonding, dipole-dipole interactions, and London dispersion forces.