Which arrows represent the phase transitions in which heat energy is gained? O 1,2, and 3
O 2,3, and 5
O 3, 4, and 5
O 4, 5, and 6

A. 1, 2, and 3

Explanation:

The phase transitions represented by the arrows in which heat energy is gained are 1, 2 and 3.

1 represents the phase transition that occurs when liquid changes to gas. This process is known as vaporization. The heat energy gained brings about this process.

2 represents the phase transition that occurs when solid changes to liquid. Heat energy is applied to achieve through the process of melting.

3 represents the phase transition that occurs when solid changes to gas. When heat energy is applied, sublimation occurs.

In phase transition, whenever heat energy is applied, it causes a phase change. The heat energy applied breaks the bonds that exists between the molecules of the substance. Thus, the heat is used to break the bonds that exist in the solid and then it turns into a liquid phase.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.