As indicated in figure 8 a given pure substance at room temperature (20°C) was heated While heating the pure substance, the temperature started to rise up. After 7 minutes, the temperature reached 70°C and stayed as it is even when heated for 30 minutes more. What does the 70°C indicate?
Answers & Comments
Evaporation is a phase transition from the liquid phase to the gas phase that occurs at temperatures below the boiling point at a given pressure.
For molecules of a liquid to evaporate, they must be located near the surface, be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase intermolecular forces.
Boiling is a phase transition from the liquid phase to the gas phase that occurs at or above the boiling temperature.
Boiling is the rapid vaporization of a liquid and occurs when a liquid is heated to its boiling point. A liquid’s boiling point is the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environment (air).