The increase in potential energy during the melting of ice into liquid water can be explained by the changes in molecular structure and intermolecular forces.
When ice is in its solid state, the water molecules are arranged in a rigid, orderly lattice structure due to strong hydrogen bonds. In this arrangement, the molecules are held closely together, and their positions are fixed, resulting in a lower potential energy state.
As heat is applied to the ice, the temperature rises until it reaches the melting point. At this point, the added energy does not increase the temperature further but instead is used for the phase change from solid to liquid. This energy is referred to as the latent heat of fusion. During this phase change, the heat energy disrupts the hydrogen bonds that hold the ice molecules together, allowing them to move more freely.
As the hydrogen bonds are broken and the structure becomes more disordered, the potential energy of the water molecules increases because they are now in a higher energy state compared to when they were in the solid state. In the liquid state, the molecules have more freedom of movement and are no longer in a fixed position relative to one another, which contributes to the increase in potential energy.
Thus, the potential energy increases during the melting of ice because the transition from a structured solid to a more fluid liquid requires energy to overcome intermolecular attractions, resulting in a higher energy state for the molecules.
1 answer