3.4 Phase Changes

Which example involves a phase change in which heat energy is released by the substance? A. freezing ice cream B. cooking a pot of soup C. melting ice under sunlight D. watching frost disappear into air

A. freezing ice cream

When does carbon dioxide absorb the most heat energy? A. during freezing B. during deposition C. during sublimation D. during condensation

C. during sublimation

Which best describes the energy change that takes place during deposition? A. Heat energy is released by the substance. B. Heat energy is maintained by the substance. C. Heat energy is slowly gained by the substance. D. Heat energy is quickly absorbed by the substance.

A. Heat energy is released by the substance.

Consider the statement below. "When nitrogen is liquefied, heat is released." Is this statement true or false? A. It is false because nitrogen absorbs heat when it is liquefied. B. It is false because nitrogen cannot absorb enough heat to liquefy. C. It is true because heat is released when a gas changes to a liquid. D. It is true because heat is released when a liquid changes to a gas.

C. It is true because heat is released when a gas changes to a liquid.

Consider the temperature versus time graph At what temperature is the boiling point of this substance? A. at 0°C B. between 0°C and 100°C C. at 120°C D. above 120°C

C. at 120°

Water is initially present in a state where its molecules are far apart. During a change of state, its molecules slow down. Which change of state has most likely taken place? A. from a gas to a liquid B. from a liquid to a gas C. from a solid to a liquid D. from a gas to a plasma

A. from a gas to a liquid

A solid substance turns into a liquid. Which best describes this change? A. substance that has a specific volume changes to a substance that has a specific shape. B. substance that has a specific volume changes to a substance that has a different volume. C. substance that has a specific shape and volume changes to a substance that has a specific volume. D. substance that has a specific volume changes to a substance that has a specific shape and volume.

C. substance that has a specific shape and volume changes to a substance that has a specific volume.

Which best explains the relationship between evaporation and temperature? A. A liquid evaporates slower at lower temperatures because the molecules are more spread apart and are not pushed as easily from the liquid's surface. B. A liquid evaporates faster at lower temperatures because the attractions are decreased and more particles can escape the surface of the liquid. C. A liquid evaporates slower at higher temperatures because the vapor pressure of the liquid is higher, so fewer molecules can escape the surface. D. A liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome attractions in the liquid.

D. A liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome attractions in the liquid.

Which energy change occurs during boiling? A. Some heat energy of the substance is lost. B. Heat energy of the substance remains the same. C. Most heat energy of the substance is lost. D. Heat energy is absorbed by the substance.

D. Heat energy is absorbed by the substance