VARIATION OF S.V.P OF WATER WITH TEMPERATURE

VARIATION OF S.V.P OF WATER WITH TEMPERATURE

TITLE: OF THE EXPERIMENT: 

Variation of saturated vapour pressure (S.V.P) of water with temperature using a capillary tube with a water index.

APPARATUS:

Thick – walled capillary tube closed at one end, multimetre scale (ruler) , rubber bands, thermometer, stirrer.

DIAGRAM:

Throughout the heating experiment, the air below the water index is saturated and is at a constant pressure atmospheric. At any temperature the partial pressure of air is.

P –Px

Where P = atmospheric pressure.

Px = S.V.P at the temperature (X = 1 or 2).

PROCEDURE:

The capillary tubing was warmed gently over to burden burner (while rotating to avoid cracking), and the open end was dipped into cold water. A thread of water that entered the capillary tubing was displaced to about the middle by tapping, the capillary was attached to the ruler using the rubber – bands and was placed in a beaker that had water in it.

The open end of the tubing was opened to the air and the water was heated slowly and stirred regularly, while the length of the  trapped moist air was measured at temperature intervals of about 5°C between 25°C and 60°C. Heating was then stopped when water index had reached the top of the tubing. The source of heat was removed and the apparatus was allowed to the cool, the measurement of the length of the moist air at the same temperature was repeated.

PRECAUTION OF VARIATION OF S.V.P OF WATER WITH TEMPERATURE

1 . The capillary tube was rotated during heating to prevent cracking.

2 . The water bath was stirred regularly during heating to prevent uneven spread of temperature.

3 . Thermometer with calibration from 0°C to 100°C was used to prevent inaccurate reading of temperature