Question

which statement is false?
a) water molecules orient so their oxygen atoms point toward an anion in solution.
b) hydrated ions are stabilized by the surrounding water molecules.
c) when an ionic compound dissolves in water, the ions interact with the permanent dipoles of the water molecules.
d) water molecules in the inner sphere of hydration of an ion are involved in ion - dipole interactions.
e) liquid ammonia, nh₃, like water, could experience ion - dipole interactions with dissolved ions.

Explanation:

• For option a: Water molecules are polar. The oxygen atom is partially negative. An anion is negatively charged. Like charges repel. So water molecules should orient with their hydrogen atoms (partially positive) toward an anion, not oxygen atoms.
• For option b: Hydrated ions are stabilized by the surrounding water molecules through ion - dipole interactions.
• For option c: When an ionic compound dissolves in water (a polar solvent), the ions (charged) interact with the permanent dipoles of water molecules (ion - dipole interaction).
• For option d: Water molecules in the inner sphere of hydration of an ion are directly involved in ion - dipole interactions.
• For option e: Liquid ammonia (\(NH_3\)) is a polar molecule (due to its molecular geometry and electronegativity differences). So, like water, it can experience ion - dipole interactions with dissolved ions.

Answer:

A. Water molecules orient so their oxygen atoms point toward an anion in solution.