SDSU Chemistry Placement Practice Test

In water, the primary intermolecular force is hydrogen bonding, which arises from the unique structure of the water molecule. Each water molecule consists of one oxygen atom covalently bonded to two hydrogen atoms, resulting in a bent shape. This shape leads to an uneven distribution of electron density, making water a polar molecule. The oxygen atom is more electronegative than the hydrogen atoms, creating partial positive charges on the hydrogens and a partial negative charge on the oxygen.

Hydrogen bonds form when the positively charged hydrogen atoms of one water molecule are attracted to the negatively charged oxygen atom of another water molecule. These hydrogen bonds are relatively strong for intermolecular forces and significantly impact water's physical properties, such as its high boiling point, surface tension, and solvent capabilities.

The other options represent different types of intermolecular interactions. Ionic bonding involves the electrostatic attraction between positively and negatively charged ions and is much stronger than the forces present in water. Van der Waals forces are weaker interactions due to temporary dipoles in molecules and are not the primary force in water. Dipole-dipole interactions occur between polar molecules but do not account for the strength and prevalence of hydrogen bonds in water's structure. Thus, hydrogen bonding is the dominant intermolecular force in