Understanding Phase Diagrams

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

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

• It is where two phases are in equilibrium.

• It is where all three phases coexist in equilibrium.

• It is the point where a substance becomes a supercritical fluid.

Which phase change is described as the transition from liquid to gas?

• Fusion

• Sublimation

• Vaporization

• Condensation

What phase change occurs when a solid turns directly into a gas?

• Vaporization

• Fusion

• Sublimation

• Condensation

What happens to a substance at the critical point?

• It can no longer undergo liquid-gas phase transitions.

• It becomes a solid.

• It can only exist as a gas.

• It becomes a supercritical fluid.

What is a supercritical fluid?

• A state where a substance is only a liquid.

• A state where a substance is only a gas.

• A state where a substance is both a solid and a liquid.

• A state where a substance is neither a liquid nor a gas.

Why does carbon dioxide not exist as a liquid at one atmosphere?

• Because its critical point is below one atmosphere.

• Because its triple point is above one atmosphere.

• Because it sublimes directly from solid to gas at one atmosphere.

• Because its triple point is below one atmosphere.

What is unique about the solid-liquid line of equilibrium in water's phase diagram?

• It is horizontal.

• It has a negative slope.

• It has a positive slope.

• It is vertical.

Why is the negative slope of water's solid-liquid line important for life on Earth?

• It allows ice to sink, insulating aquatic life.

• It causes water to evaporate quickly.

• It allows ice to float, insulating aquatic life.

• It prevents water from freezing.

How does the negative slope of water's solid-liquid line affect ice hockey players?

• It causes the ice to melt faster.

• It prevents the ice from melting.

• It makes the ice more slippery.

• It makes the ice less slippery.

What is the effect of hydrogen bonding on the density of ice compared to liquid water?

• Ice is denser only at high pressures.

• Ice is denser than liquid water.

• Ice is less dense than liquid water.

• Ice and liquid water have the same density.