Question

A white substance melts with some decomposition at \(730^{\circ} \mathrm{C}\). As a solid, it does not conduct electricity, but it dissolves in water to form a conducting solution. Which type of solid (molecular, metallic, covalent- network, or ionic) might the substance be?

Short answer

The given white solid has a high melting point (730°C), does not conduct electricity as a solid, and dissolves in water to form a conducting solution. Based on these properties, it is most likely an ionic solid.

Step-by-step solution

Analyze the properties of each type of solid

Let's analyze the properties of molecular, metallic, covalent-network, and ionic solids. 1. Molecular solids: Low melting points, poor electrical conductivity, and typically dissolve in nonpolar solvents. 2. Metallic solids: High melting points, good electrical conductivity, and insoluble in most solvents. 3. Covalent-network solids: Very high melting points, poor electrical conductivity, and insoluble in most solvents. 4. Ionic solids: High melting points, poor electrical conductivity in the solid state, and they dissolve in water to form conducting solutions.

Match the properties to determine the type of solid

The white solid has the following properties: - Melts at 730°C, indicating a relatively high melting point. - Doesn't conduct electricity as a solid. - Dissolves in water to form a conducting solution. Based on these properties, we can say the solid is most likely an ionic solid as its properties fit this type the best: - High melting points. - Poor electrical conductivity in the solid state. - They dissolve in water to form conducting solutions.