EXERCISE 16 



WHAT IS THE RELATIVE HUMIDITY IN THE ROOM? 



Materials. Data from the preceding exercise ; the table on page 23, " Elements of General 

 Science." 



Directions. From the preceding exercise (Additional problems) obtain the weight of water vapor 

 per cubic foot of space in the room at the time the experiment was performed. Refer to the table to 

 find out what weight of water vapor per cubic foot of space would have been present if the space 

 had been saturated at the temperature observed at the time of the experiment. What percentage of 

 the latter weight was the weight of water actually present ? This was the relative humidity. Write 

 a definition of the term relative humidity. State the difference between relative and absolute 

 humidity. 



Additional problems. When raindrops are forming and falling from the atmosphere, what is the relative 

 humidity of the atmosphere ? 



It is sometimes said that the air in artificially heated rooms is like the air of a desert. By determining 

 the relative humidity in the classroom on each of several days, see what basis there is for this statement. 

 How can this condition be changed ? 



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