Question

question 1 6 pts which phase change releases energy? o h₂o (l) → h₂o (g) o h₂o (s) → h₂o (l) o h₂o (l) → h₂o (s) o h₂o (s) → h₂o (g) question 2 6 pts which of the following processes absorbs energy? o condensation of water on a wind shield of a car o formation of copper (ii) oxide from copper and oxygen o ball rolling down a hill o formation of ice from liquid water

Explanation:

• For Question 1: Phase changes from a higher - energy state to a lower - energy state release energy. Liquid to solid (freezing) is such a change. In $H_2O(l)\to H_2O(s)$, water goes from a more energetic liquid state to a less energetic solid state, releasing energy. The other options represent processes that require energy input (liquid to gas, solid to liquid, solid to gas).
• For Question 2: Processes that go from a lower - energy state to a higher - energy state absorb energy. Condensation (gas to liquid) releases energy, formation of copper (II) oxide is an exothermic reaction releasing energy, ball rolling down a hill converts potential energy to kinetic energy without absorbing energy. The formation of ice from liquid water releases energy. None of the given options are correct for energy - absorbing processes. But if we consider the principle, processes like melting, evaporation, sublimation are energy - absorbing.

Answer:

Question 1: $H_2O(l)\to H_2O(s)$
Question 2: None of the above options are correct for an energy - absorbing process.