What is the relationship between heat of vaporization and vapor pressure?
When a liquid is heated, its molecules obtain sufficient kinetic energy to overcome the forces holding them in the liquid and they escape into the gaseous phase. By doing so, they generate a population of molecules in the vapor phase above the liquid that produces a pressure—the vapor pressure of the liquid.
Does heat of vaporization change with pressure?
As the pressure is increased, the increased pressure helps in binding the molecules. Therefore less amount of heat needs to be removed. So, as pressure increases, latent heat of vapourisation decreases while latent heat of condensation decreases.
What phase transition occurs in vaporization?
Phase Transition: Liquid to Gas Vaporization of a sample of liquid is a phase transition from the liquid phase to the gas phase. There are two types of vaporization: evaporation and boiling. Evaporation occurs at temperatures below the boiling point, and occurs on the liquid’s surface.
What is the transition from liquid to vapor called?
Evaporation is the process by which a liquid turns into a gas.
What is the relationship between heat of vaporization and the strength of intermolecular forces?
The stronger the intermolecular forces, the higher the heat of vaporization.
What factors affect heat of vaporization?
Factors Affecting Vaporization
- temperature of liquid phase.
- number of moles of liquid phase.
- vapor pressure of evaporated phase.
- heat of vaporization: quantity of energy required to convert liquid to gas at a constant temperature. ether: 26.0 kJ/mole, boiling point = 34.6 oC.
How do you find heat of vaporization with temperature and pressure?
If the problem provides the two pressure and two temperature values, use the equation ln(P1/P2)=(Hvap/R)(T1-T2/T1xT2), where P1 and P2 are the pressure values; Hvap is the molar heat of vaporization; R is the gas constant; and T1 and T2 are the temperature values.
What happens in phase transition?
A phase transition is a change in state from one phase to another. The defining characteristic of a phase transition is the abrupt change in one or more physical properties with an infinitesimal change in temperature.
What happens during a phase transition?
During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, or others. For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume.
What is the result of vaporization?
vaporization, conversion of a substance from the liquid or solid phase into the gaseous (vapour) phase. If conditions allow the formation of vapour bubbles within a liquid, the vaporization process is called boiling. Direct conversion from solid to vapour is called sublimation.
What is the heat of vaporization?
Also known as enthalpy of vaporization, the heat of vaporization (∆H vap) is defined by the amount of enthalpy (heat energy) that is required to transform a liquid substance into a gas or vapor.
What is the relationship between vapor pressure and temperature?
In mathematical terms, the relationship between the vapor pressure of a liquid and temperature is described in the Clausius-Clayperon equation,
Why is the heat of vaporization measured in Jmol?
It is measured in Joules per mole (J/mol), or sometimes in Calories (C). The heat of vaporization always has a positive value because enthalpy is always added to a system in order to vaporize a liquid. As the molecules gain more kinetic energy, they become more likely to separate from the liquid and become a gas.
What is the importance of vaporization in the water cycle?
A. It is not important. B. It takes a lot of heat to vaporize water, which is important for the water cycle and temperature of the Earth. C. This causes water to easily vaporize, which helps humidify the world. 5. In a liquid state, a certain substance forms many temporary, but strong bonds between molecules.