Question

Ionic solids are characterized by

• A. Low melting points.
• B. High vapor pressure.
• C. Solubility in polar solvents.
• D. Good conductivity in solid-state.

Answer 1

The correct option is C

Solubility in polar solvents.

Explanation for Correct Option:

Option (C): Solubility in polar solvents.

• An ionic bond is defined as the attractive electrostatic force that is present between two oppositely charged ions.
• The formation of an ionic bond occurs when excess electrons from an anion are transferred to a cation in order to attain their nearest inert gas configuration.
• Strong electrostatic forces act on ionic compounds, they are tightly packed with each other to form a crystal lattice.
• Generally, these crystal lattices are very hard to break.
• But, in a liquid state, the ions dissociate into ions that can move freely in the solution.
• Hence, ionic solids are soluble in polar solvents.

Explanation for Incorrect Option:

Option (A): Low melting points.

• Crystal lattices in ionic solids form such strong bonds with each other which is stronger than the kinetic energy of the ions at normal room temperatures.
• Hence, the ions are unable to break away.
• Ionic solids are characterized by very high melting points.

Option (B): High vapour pressure.

• Since ionic solids are hard and brittle they have a low vapour pressure.
• Hence, ionic solids are not characterized by high vapour pressure.

Option (D): Good conductivity in solid-state.

• The particles in ionic solids are fixed in their positions and have very little freedom for movement.
• Hence, ionic solids are characterized by poor conduction in solid states.

Therefore, ionic solids are characterized by option (C): Solubility in polar solvents.