AP Chemistry: Molecular Solids

What are molecular solids primarily composed of and how are their constituent particles held together?

• Atoms held together by covalent bonds

• Molecules held together by intermolecular forces

• Ions held together by ionic bonds

• Metal cations held together by metallic bonds

What types of intermolecular forces attract molecules in molecular solids?

• Dipole-dipole or hydrogen bonds if polar; London Dispersion Forces if nonpolar

• Ionic bonds if polar; metallic bonds if nonpolar

• Covalent bonds if polar; ionic bonds if nonpolar

• Metallic bonds if polar; hydrogen bonds if nonpolar

What is a characteristic melting point of molecular solids and why?

• High melting points because strong covalent bonds must be broken.

• High melting points because strong intermolecular forces must be broken.

• Low melting points because weak intermolecular forces require less heat to break.

• Low melting points because the molecules themselves are broken down.

What type of change occurs when a molecular solid melts, and what happens to the covalent bonds within the molecules?

• A chemical change where covalent bonds within molecules are altered.

• A chemical change where intermolecular forces are formed.

• A physical change where molecules are converted into different substances.

• A physical change where covalent bonding within molecules is not altered.

Are molecular solids typically electrically conductive, and what is the reason for this property?

• They are typically electrically conductive because they have mobile charged particles.

• They are not typically electrically conductive because molecules are neutral and electrons are tightly held.

• They are always electrically conductive due to the presence of free electrons.

• Their electrical conductivity varies greatly depending on the type of covalent bonds present.