The video tutorial explains the properties of ionic and covalent compounds, focusing on their ability to conduct electricity, their melting points, and their solubility in different solvents. Ionic compounds, composed of positive and negative ions, can conduct electricity in liquid form due to free-moving ions. They have high melting points due to strong ionic bonds. Covalent compounds, made of neutral molecules, do not conduct electricity and have lower melting points due to weak intermolecular forces. Solubility varies: ionic compounds dissolve in water but not in organic solvents, while covalent compounds dissolve in organic solvents but not in water.

What happens to the ions in lead bromide when it is heated to a liquid state?

• They become neutral.

• They become fixed in place.

• They are free to move.

• They form a gas.

Why can molten ionic compounds conduct electricity?

• Because they are solid.

• Because they have a high melting point.

• Because they have free-moving electrons.

• Because they have free-moving ions.

Why do covalent compounds like naphthalene not conduct electricity?

• They have no charged particles.

• They have a high melting point.

• They have free-moving ions.

• They are soluble in water.

What is a characteristic feature of the crystal lattice in ionic compounds?

• Free-moving electrons.

• Low melting points.

• Weak intermolecular forces.

• Strong forces between ions.

Why do ionic compounds generally have high melting points?

• Due to strong forces between ions.

• Due to weak intermolecular forces.

• Because they conduct electricity.

• Because they are soluble in water.

What happens to the forces between molecules when a covalent compound is melted?

• They form a crystal lattice.

• They are broken.

• They remain unchanged.

• They become stronger.

Why do covalent compounds generally have low melting points?

• Due to strong intermolecular forces.

• Due to weak intermolecular forces.

• Because they conduct electricity.

• Because they are soluble in water.

Why are most ionic compounds soluble in water?

• Water molecules cannot separate the ions.

• They have weak intermolecular forces.

• They have low melting points.

• Water molecules can separate the ions.

Why are covalent compounds generally insoluble in water?

• They conduct electricity.

• They have strong ionic bonds.

• Water molecules cannot separate the molecules.

• Water molecules can separate the molecules.

What is the general solubility behavior of covalent compounds in organic solvents?

• They conduct electricity in organic solvents.

• They are soluble in water.

• They are soluble in organic solvents.

• They are insoluble in organic solvents.