Which of the following is a characteristic property of ionic compounds?

• A. They are generally insoluble in water.
• B. They have high melting and boiling points.
• C. They conduct electricity in solid state.
• D. They are malleable and ductile.

Answer: (B)

Verified step by step guidance

1. Understand the nature of ionic compounds: Ionic compounds are formed by the electrostatic attraction between positively charged cations and negatively charged anions.
2. Recall the physical properties of ionic compounds: Because of the strong ionic bonds, ionic compounds typically have high melting and boiling points, meaning they require a lot of energy to break the bonds and change state.
3. Consider solubility: Ionic compounds are generally soluble in water because water molecules can stabilize the ions by surrounding them, which helps dissolve the compound.
4. Evaluate electrical conductivity: Ionic compounds do not conduct electricity in the solid state because the ions are fixed in place within the crystal lattice; however, they do conduct electricity when melted or dissolved in water because the ions are free to move.
5. Assess mechanical properties: Ionic compounds are usually brittle rather than malleable or ductile because when layers of ions shift, like charges repel and cause the crystal to break.