Intermolecular Forces and Phase Changes

The video provides a review of Unit 7, focusing on heating curves, phase changes, and energy conservation. It explains specific heat capacities, phase diagrams, and the behavior of carbon dioxide. The video also covers intermolecular forces, solubility, and offers test preparation advice.

What happens to the temperature of a substance during a phase change?

• It decreases.

• It remains constant.

• It fluctuates randomly.

• It increases.

Why is the vaporization line typically longer than the fusion line on a heating curve?

• Because solids have higher specific heat capacities.

• Because gases have lower specific heat capacities.

• Because breaking intermolecular forces requires more energy.

• Because breaking crystal structures requires more energy.

Which phase of water has the highest specific heat capacity?

• Gas

• Solid

• Liquid

• Plasma

What is the significance of the triple point in a phase diagram?

• It is the point where only the liquid phase exists.

• It is the point where the gas phase is most stable.

• It is the point where only the solid phase exists.

• It is the point where all three phases coexist.

Why can carbon dioxide sublimate under normal atmospheric conditions?

• Because its triple point is below normal room pressure.

• Because its triple point is above normal room pressure.

• Because it has a low boiling point.

• Because it has a high melting point.

What determines the boiling point of a liquid?

• The mass of the liquid molecules.

• The color of the liquid.

• The strength of its intermolecular forces.

• The volume of the liquid.

What happens to vapor pressure when intermolecular forces are strong?

• Vapor pressure decreases.

• Vapor pressure increases.

• Vapor pressure remains constant.

• Vapor pressure fluctuates.

Which intermolecular force is the strongest?

• London dispersion forces

• Dipole-dipole interactions

• Hydrogen bonds

• Van der Waals forces

What type of molecules can form hydrogen bonds?

• Molecules with symmetrical geometry

• Molecules with hydrogen bonded to nitrogen, oxygen, or fluorine

• Molecules with only carbon and hydrogen

• Nonpolar molecules

What determines whether a substance is soluble in another?

• The color of the substances

• The size of the molecules

• The temperature of the substances

• The similarity of their intermolecular forces