L56 Gas Density

What is unique about Earth in terms of liquid water?

• It is the only planet in the solar system with no liquid water on its surface.

• It is the only planet in the solar system with so much liquid water on its surface.

• It is one of many planets in the solar system with a moderate amount of liquid water on its surface.

• It has less liquid water on its surface compared to other planets in the solar system.

Answer explanation

Earth is the only planet in the solar system with so much liquid water on its surface, making it unique in this aspect.

What are the phase changes of water mostly responsible for on Earth?

• The movement of moisture around the planet.

• The constant temperature of the planet.

• The density of the planet's atmosphere.

• The rotation of the Earth on its axis.

Answer explanation

The phase changes of water are mostly responsible for the movement of moisture around the planet, impacting weather patterns and climate.

What happens to the density of water molecules when they change from liquid to gas?

• The density remains unchanged.

• The density decreases dramatically.

• The density increases slightly.

• The density is halved.

Answer explanation

When water molecules change from liquid to gas, the density decreases dramatically due to the increased distance between molecules in the gas phase.

Why is it not easy to measure the density of gases compared to liquids and solids?

• Gases are always heavier than liquids and solids.

• Gases do not have a definite volume or shape.

• Gases cannot be placed on a balance.

• Gases are less common than liquids and solids.

Answer explanation

Gases do not have a definite volume or shape, making it challenging to measure their density compared to liquids and solids.

What is sublimation in the context of phase changes?

• The process where a solid changes directly into a liquid.

• The process where a liquid changes directly into a gas.

• The process where a gas changes directly into a solid.

• The process where a solid changes directly into a gas.

Answer explanation

Sublimation is the process where a solid changes directly into a gas, skipping the liquid phase.

At what temperature does carbon dioxide sublimate?

• 0°C

• 100°C

• −78°C

• 32°F

Answer explanation

Carbon dioxide sublimates at -78°C, which means it changes directly from a solid to a gas without passing through the liquid phase.

What is the approximate volume that one gram of gaseous CO₂ occupies?

What is the approximate volume that one gram of solid CO₂ occupies?

What is the density of solid carbon dioxide, CO_2(s)?

• 0.0019 g/mL

• 1.56 g/mL

• 800 g/mL

• 0.00019 g/mL

Answer explanation

Lesson 56, page 296, references the density of carbon dioxide in different states.

How does the volume of gas carbon dioxide, CO_2(g), compare to its solid form?

• The volume of the gas is nearly 800 times smaller.

• The volume of the gas is nearly 800 times larger.

• The volume of the gas is half the size.

• The volume of the gas is twice the size.

Answer explanation

The volume of the gas is nearly 800 times larger because gases have much higher volumes compared to their solid forms due to the increased molecular motion.