PHY_10_12_V2_DM_Air humidity,dew point

Application 1

Humidity

The process of liquid transition from liquid to gas is called ... (vaporization)

The process of gas transition into a liquid state is called ... (condensation)

Steam formation is divided into ... (evaporation and boiling)

Vaporization from the free surface of the liquid is called ... (evaporation)

Vaporization not only from the free surface of the liquid, but also over the entire volume of the liquid that occurs at a specific temperature for a given liquid, is called ... (boiling)

If the number of molecules emitted from a liquid during evaporation exceeds the number of those returned, the steam is called ... (unsaturated)

If the number of molecules emitted from a liquid during evaporation is equal to the number of those that have returned, then the vapor is called ... (saturated)

The temperature at which the unsaturated water vapor becomes saturated is called ... (dew point)

Application 2

Practical work

Aim: determines the relative humidity.

Equipment: laboratory thermometer, cuvette with water, a piece of bandage.

Procedure:

1.   Measure the temperature of the air in the classroom using thermometer and write it down in a copybook.

2.   Moisten a piece of dressing and wrap a thermometer in it. Watch the temperature drop. Once the temperature has settled, record the reading of the thermometer.

3.   Find the temperature difference between dry and wet thermometer and, using psychrometric table, determine the relative humidity in the class.

Safety rules:

Remember that a glass thermometer must be handled carefully. After completing the task, do not forget to put the thermometer in the case.