define how intermolecular forces affect rates the vaporization, evaporation, and also condensation.

You are watching: What happens to the temperature of the remaining liquid


On the roof the the house in the photo below is a an equipment known together a "swamp cooler". This item of devices traces its origin earlier to the old Egyptians who hung wet blankets across the doors of their homes. As the warm air passed through the blankets, water would evaporate and also cool the air. The nobility went one step further and had servants pan wet cloths end jugs of water come get much more evaporation and also cooling.

*
Figure (PageIndex1): A residence with a swamp cooler attached come the roof.

The origin of the ax "swamp cooler" is not known - they certainly don"t work-related in a swamp. Ideal conditions for cooling include a high temperature (over (80^ exto extF)) and also a short humidity (preferably less than (30\%)). These coolers job-related well in desert areas, yet don"t carry out any cooling in the humid locations of the country.


Evaporation

A puddle of water left undisturbed ultimately disappears. The liquid molecules escape right into the gas phase, becoming water vapor. Vaporization is the procedure in which a fluid is converted to a gas. Evaporation is the switch of a liquid to that is vapor listed below the boil temperature the the liquid. If the water is instead kept in a close up door container, the water vapor molecules do not have a opportunity to escape into the surroundings and also so the water level does no change. As part water molecules become vapor, one equal number of water vapor molecule condense ago into the liquid state. Condensation is the adjust of state indigenous a gas to a liquid.

*
Figure (PageIndex2): Evaporation (A) and condensation (B).

In order because that a fluid molecule to escape into the gas state, the molecule need to have sufficient kinetic energy to get rid of the intermolecular attractive pressures in the liquid. Recall that a offered liquid sample will have molecules with a wide selection of kinetic energies. Fluid molecules that have this certain threshold kinetic energy escape the surface and also become vapor. Together a result, the liquid molecules that continue to be now have lower kinetic energy. As evaporation occurs, the temperature that the staying liquid decreases. You have observed the results of evaporative cooling. ~ above a warm day, the water molecules in her perspiration absorb body heat and evaporate native the surface ar of your skin. The evaporating procedure leaves the continuing to be perspiration cooler, which subsequently absorbs much more heat from your body.

A provided liquid will certainly evaporate much more quickly as soon as it is heated. This is due to the fact that the heating process results in a greater portion of the liquid"s molecules having actually the essential kinetic energy to to escape the surface ar of the liquid. The figure listed below shows the kinetic energy distribution of liquid molecules at 2 temperatures. The numbers of molecule that have the forced kinetic energy to evaporate are displayed in the shaded area under the curve in ~ the right. The higher temperature liquid (left( T_2 ight)) has an ext molecules the are capable of escaping into the vapor phase than the lower temperature liquid (left( T_1 ight)).

*
vaporize. In ~ this allude the liquid starts to boil. The boiling point is the temperature at which the vapor pressure of a liquid is same to the exterior pressure. The figure below illustrates the cook of liquid.

*
Figure (PageIndex4): Comparison in between evaporation and also boiling.

In the photo on the left, the fluid is listed below its cook point, yet some of the liquid evaporates. ~ above the right, the temperature has actually been raised until bubbles begin to type in the human body of the liquid. Once the vapor pressure inside the balloon is equal to the external atmospheric pressure, the bubbles climb to the surface of the liquid and burst. The temperature in ~ which this process occurs is the boiling suggest of the liquid.

See more: How Many Cm Is A Yard S To Centimeters, Yards To Centimeters

The normal boiling point is the temperature at which the vapor push of the liquid is equal to conventional pressure. Due to the fact that atmospheric pressure can adjust based ~ above location, the boiling point of a liquid changes with the exterior pressure. The normal boiling suggest is a constant because it is characterized relative to the conventional atmospheric pressure of (760 : extmm : ceHg) (or (1 : extatm) or (101.3 : extkPa)).