The change of state from ice to water is accompanied by ______.

Concept:

Change of state:

• It is a physical change in a matter.
• They are reversible changes and do not involve any changes in the chemical makeup of the matter.
• Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.

Melting:

• A change of a solid into a liquid when heat is applied.
• In a pure crystalline solid, this process occurs at a fixed temperature called the melting point; an impure solid generally melts over a range of temperatures below the melting point of the principal component.
•  Examples: Ice cubes when taken out from the freezer and placed at room temperature, it changes into a liquid, so here ice cubes melt to form water.

Explanation:

• Every change of state is accompanied by a transfer of energy, as can be seen in our daily lives.
• We can't make ice cubes on a summer day without plugging in a refrigerator, for example. Nor can we boil water without turning on a burner.
• In fact, water is a good example for illustrating the energy transfers that occur during any change of state.
• It requires 80 calories to melt 1 gram of ice (a quantity called the latent heat of fusion).
• While the ice is melting, it remains at a temperature of 0°C It requires 100 calories to raise the temperature of the resulting melted ice to 100°C (1 calorie per gram), and then 580 calories to convert that water into steam (the latent heat of vaporization).
• An endothermic process, meaning it requires heat to occur. As ice absorbs heat, the temperature remains constant at the melting point until all the ice has converted to water. Only after all the ice has melted will the temperature of the water begin to increase.