Phase Changes: Chemistry Flashcards

Questions and Answers

What is a phase change?

A change in chemical composition

A change from one state to another without changing chemical composition (correct)

The process of evaporation

An increase in temperature

What does melting refer to?

The process of becoming liquefied by heat.

What temperature defines freezing?

Below 32°F (0°C).

What is vaporization?

The phase transition from liquid to vapor. Signup and view all the answers

What happens during condensation?

Water collects as droplets on a cold surface when humid air contacts it. Signup and view all the answers

What does sublimation mean?

The transition from solid to gas without passing through the liquid phase. Signup and view all the answers

What is the definition of heat of fusion?

The enthalpy of fusion of a substance. Signup and view all the answers

What is an exothermic change?

A chemical reaction that releases energy by light or heat. Signup and view all the answers

What does endothermic change mean?

A chemical reaction that absorbs heat. Signup and view all the answers

What is the definition of evaporation?

A type of vaporization that occurs from the surface of a liquid into a gaseous phase. Signup and view all the answers

What is heat of vaporization?

The amount of energy needed to transform a substance from liquid to gas. Signup and view all the answers

What does boiling refer to?

Bringing a liquid to the temperature at which it bubbles and turns to vapor. Signup and view all the answers

Study Notes

Phase Changes in Chemistry

Phase change refers to the transformation of a substance from one state (solid, liquid, or gas) to another without altering its chemical composition.
Melting: The process of a solid becoming a liquid due to heat.
Freezing: Occurs when a liquid transitions to a solid state, typically at or below 32°F (0°C).
Vaporization: A transition from the liquid phase to vapor, encompassing processes like boiling and evaporation.
Condensation: Involves the formation of water droplets on a cold surface from humid air interacting with it.
Sublimation: The direct transition from solid to gas, bypassing the liquid phase entirely.
Deposition: The process of gas transforming directly into a solid, often seen in frost formation.

Thermodynamic Concepts

Heat of Fusion: Enthalpy change associated with the melting of a substance.
Exothermic Change: A chemical reaction that releases energy in the form of heat or light.
Endothermic Change: A reaction that absorbs heat, often causing temperature drops in surroundings or requiring heat generation for organisms.
Evaporation: A surface phenomenon where liquid molecules transition to gas in an unsaturated environment.
Heat of Vaporization: The energy needed to convert a liquid into vapor, essential for understanding boiling and evaporation.
Boiling: The action of heating a liquid to its boiling point, leading to the formation of vapor bubbles.

Description

Test your knowledge of phase changes in chemistry with these flashcards. Learn important definitions such as melting, freezing, and vaporization. This quiz is perfect for reinforcing concepts related to states of matter.