Phase Diagrams and Heating Curves

Front

What is a phase diagram?

Back

A graphical representation showing the states of matter (solid, liquid, gas) of a substance at different temperatures and pressures.

Front

What does the term 'melting point' refer to?

Back

The temperature at which a solid becomes a liquid.

Front

What is the significance of the normal boiling point?

Back

The temperature at which a liquid's vapor pressure equals the external pressure, typically measured at 1 atmosphere.

Front

Define sublimation.

Back

The process in which a solid changes directly into a gas without passing through the liquid state.

Front

What occurs during a phase change?

Back

A transition between solid, liquid, and gas states, involving energy changes but no change in temperature.

Front

What is the triple point in a phase diagram?

Back

The unique set of conditions at which all three phases (solid, liquid, gas) coexist in equilibrium.

Front

Explain the difference between evaporation and boiling.

Back

Evaporation occurs at any temperature and only at the surface, while boiling occurs throughout the liquid at a specific temperature.

Front

What happens to temperature during a phase change?

Back

The temperature remains constant during a phase change as energy is used to change the state rather than increase temperature.

Front

What is the critical point in a phase diagram?

Back

The temperature and pressure at which the liquid and gas phases become indistinguishable.

Front

What is the role of pressure in phase changes?

Back

Pressure affects the boiling and melting points; increasing pressure raises the boiling point and can change the state of matter.