Phase Changes Assignment and quiz

Consider the temperature versus time graph below. mc021-1.jpg In which region is the substance in both the solid phase and the liquid phase? 1 2 3 4

2

Use the table to identify the phase and phase changes of the elements under the given conditions. Write the name of the substance, phase, or phase change. When the temperature in a room increases from 25°C to 33°C, ... changes from a solid to a liquid. In a lab, methane and nitrogen are cooled from -170°C to -200°C. The methane freezes and the nitrogen .... When gold is heated to 2,856°C it changes from a liquid to a...

gallium, condenses, gas

In which phase transition do molecules directly move from a state involving vibration of particles in a fixed position to a state involving random movement of high-speed particles? evaporation sublimation freezing deposition

sublimation

Consider the heating curve for water. mc024-1.jpg At what temperature does the solid start melting? -20°C 0°C 20°C 80°C

0°C

The arrows in the chart below represent phase transitions. mc014-1.jpg Which arrows represent the phase transitions in which heat energy is gained? 1, 2, and 3 2, 3, and 5 3, 4, and 5 4, 5, and 6

1,2,and 3

The diagram below shows the different phase transitions that occur in matter. mc009-1.jpg Which arrow would most likely represent the phase change that occurs when silver is poured into a mold and cools to become a solid bar? 1 3 4 5

5

The diagram below shows the different phase transitions that occur in matter. mc027-1.jpg Which statement best describes the process that arrow 1 represents? Molecules are speeding up as boiling occurs. Molecules are slowing to a stop while freezing. Molecules are slowing down during condensation. Molecules are vibrating in stationary positions.

Molecules are speeding up as boiling occurs.

What does the diagram show about phases and the phase of the substance as it is heated? Check all that apply. The substance is a gas at more than 2,000°C. The particles are close together but move in different directions between 0°C and 2,200°C. The attractions between the particles increase in region 2. The speed of the particles increases in region 5. The substance does not exist as a solid.

The particles are close together but move in different directions between 0°C and 2,200°C. The speed of the particles increases in region 5.

Consider the temperature versus time graph below. mc020-1.jpg At what temperature is the boiling point of this substance? at 0°C between 0°C and 100°C at 120°C above 120°C

at 120°C

Energy is released during which phase changes? Check all that apply. boiling condensing depositing freezing melting subliming

condensing, depositing, freezing

Which diagram represents the phase that occurs after a solid melts? diagram 1 diagram 2 diagram 3 diagram 4

diagram 1

When does carbon dioxide absorb the most heat energy? during freezing during deposition during sublimation during condensation

during sublimation

Jean has a sample of a liquid. If she changes the liquid's phase by... it, the molecules will spread out, allowing the sample to expand and fill a container of any shape or volume.

evaporating

For nitrogen, the line at -210°C will be... , which represents the....

flat, change from a solid to a liquid

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

Heat energy is absorbed by the substance.

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

Heat energy is released by the substance.

Which statement describes the appearance of a temperature-vs.-time graph? A horizontal line shows that the temperature increases at a constant rate over time. A vertical line shows that the temperature decreases at a constant rate over time. Horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. Horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases.

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

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

Which statements describe phase changes? Check all that apply. Particles in a liquid need to move more slowly in order to freeze. Attractive forces overcome the motion of particles when a solid sublimes. Attractive forces between the particles in a liquid are broken when a liquid boils. Particles in gas move fast enough to make more attractive forces when the gas condenses.

Particles in a liquid need to move more slowly in order to freeze. Attractive forces between the particles in a liquid are broken when a liquid boils.

Which statement describes how phase changes can be diagrammed as a substance is heated? The phase is on the y-axis and the temperature is on the x-axis. The temperature is on the y-axis and the phase is on the x-axis. The time is on the y-axis and the temperature is on the x-axis. The temperature is on the y-axis and the time is on the x-axis.

The temperature is on the y-axis and the time is on the x-axis.

Use kinetic-molecular theory to describe what happens when an ice cube or icicle melts. Include how energy is involved and what happens to the motion of the water molecules

Which explanations did you include in your response? Check all the boxes that apply. The particles in a solid move faster as the solid absorbs heat. The particles in a solid overcome the attractions that hold them together as the solid melts. The particles slide past one another, but are still close together during the liquid phase.

Use the information in the table to describe the temperature-vs.-time diagrams. The diagram for gallium will have flat, horizontal lines... °C. The diagram for methane will have a ... line representing the... between -183°C and -162°C. For gold, the boiling point corresponds to the y-value at ... °C of the ...

at 30 to 2,204, diagonal, liquid phase, 2,856, top horizontal line

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

freezing ice cream

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? from a gas to a liquid from a liquid to a gas from a solid to a liquid from a gas to a plasma

from a gas to a liquid