Question

Which of the following is an accurate listing of phase changes which are exothermic and phase changes which are endothermic and why?

A) Exothermic – melting, condensation
Endothermic – freezing, evaporation
Explanation: Melting and condensation release heat, causing molecules to move slower, allowing attractive forces to pull molecules closer. Freezing and evaporation absorb heat, causing molecules to move faster and break attractive forces between molecules.

B) Exothermic – melting, freezing
Endothermic – evaporation, condensation
Explanation: Melting and freezing release heat, causing molecules to move slower, allowing attractive forces to pull molecules closer. Condensation and evaporation absorb heat, causing molecules to move faster and break attractive forces between molecules.

C) Exothermic – melting, evaporation
Endothermic – freezing, condensation
Explanation: Melting and evaporation release heat, causing molecules to move slower, allowing attractive forces to pull molecules closer. Freezing and condensation absorb heat, causing molecules to move faster and break attractive forces between molecules.

D) Exothermic – freezing, condensation
Endothermic – melting, evaporation
Explanation: Freezing and condensation release heat, causing molecules to move slower, allowing attractive forces to pull molecules closer. Melting and evaporation absorb heat, causing molecules to move faster and break attractive forces between molecules.

Answer 1

The correct exothermic phase changes are freezing and condensation, while the endothermic phase changes are melting and evaporation. This is due to the absorption or release of heat associated with changes in molecular motion and order.

Step-by-step explanation:

An accurate listing of the phase changes that are exothermic and those that are endothermic is as follows: Exothermic phase changes include freezing and condensation, while melting and evaporation are endothermic phase changes. This is because during freezing and condensation, heat is released into the environment as molecules slow down and their attractive forces pull them closer, resulting in a more ordered state. Conversely, melting and evaporation require an input of heat, causing molecules to move more rapidly and break the attractive forces between them, leading to a less ordered state.