Both covalent-network solids and ionic solids can have melting points well in excess of room temperature, and both can be poor conductors of electricity in their pure form. However, in other ways their properties are quite different. (a) Which type of solid is more likely to dissolve in water?

Key Concepts

Covalent-Network Solids

Covalent-network solids are materials where atoms are bonded together by a network of covalent bonds, forming a continuous structure. This results in very high melting points and hardness. Examples include diamond and silicon carbide. These solids typically do not dissolve in water due to their strong covalent bonds and lack of ionic character.

Ionic Solids

Ionic solids consist of positively and negatively charged ions held together by strong electrostatic forces known as ionic bonds. They generally have high melting points and can conduct electricity when melted or dissolved in water. Ionic solids, such as sodium chloride, are more likely to dissolve in water because the polar water molecules can effectively separate the ions.

Solubility in Water

Solubility in water refers to the ability of a substance to dissolve in water, which is influenced by the nature of the solute and solvent. Polar substances tend to dissolve well in water due to interactions with water molecules, while nonpolar substances do not. Ionic solids are typically soluble in water because the attraction between water molecules and the ions overcomes the ionic bonds holding the solid together.