Is heat lost in heating water and ice?
No. Entropy is lost, but heat energy is not lost.
To understand why heat is not lost in the process of heating water and ice, we need to consider a fundamental principle of thermodynamics called the conservation of energy. According to this principle, energy cannot be created or destroyed; it can only be transferred or transformed.
When you heat water or ice, you are supplying thermal energy to increase their average molecular kinetic energy, causing them to gain heat. The heat energy is transferred from a source, such as a stove or a heater, to the water or ice.
During this process, some of the heat energy is used to elevate the temperature of the water or ice, while the remaining heat energy is used to overcome the intermolecular forces holding the water molecules together in the solid state (for ice) or to break down the intermolecular forces between water molecules (for liquid water). This stage is known as the heat of fusion, where ice turns into liquid water.
The energy required to break the intermolecular forces is known as the latent heat, which is responsible for phase changes. After all the ice has melted, the additional heat energy raises the temperature of the liquid water until it reaches its boiling point, causing the water to transition from liquid to gas (steam). This stage is known as the heat of vaporization.
During this entire process, none of the heat energy is lost; it is only transformed from one form to another. Some heat may be dissipated into the surroundings due to factors like heat conduction or radiation, but it is not lost entirely.
So, in summary, when you heat water or ice, they absorb heat energy, which is then used to increase their temperature or facilitate phase changes. The heat energy is not lost but rather transformed into different forms of energy within the system.