Defining Boiling
Boiling is a rapid process of vaporization that occurs when a liquid is heated to its boiling point, leading to the formation of vapor bubbles throughout the entire liquid, not just at its surface. This intense bubble formation and ebullition (bubbling) are key characteristics distinguishing it from other forms of vaporization.
The Mechanism of Boiling
Boiling begins when the vapor pressure inside the liquid equals or exceeds the external pressure exerted on the liquid's surface. At this point, liquid molecules gain enough energy to overcome intermolecular forces and transition into a gaseous state, forming bubbles that rise and escape from the liquid. This phase change requires a continuous input of heat, known as the latent heat of vaporization.
A Common Example: Water Boiling
A familiar example is boiling water on a stove. As heat is applied, the water's temperature rises. Once it reaches 100°C (212°F) at standard atmospheric pressure (sea level), the water starts to boil. You observe vigorous bubbling as water vapor forms within the liquid and escapes into the air, indicating the phase transition from liquid water to gaseous steam.
Importance and Applications
Boiling is a fundamental concept with widespread applications across science, industry, and daily life. It is crucial for cooking food, sterilizing medical equipment, generating electricity in thermal power plants through steam turbines, and in chemical processes like distillation to separate liquid mixtures based on their boiling points.