298 



Exercises. 1. Classify (p. 132) each of the reactions repre- 

 sented by equations in this chapter. 



2. What are the radicals of sodium nitrite, and what their 

 valences? Justify the nomenclature. 



3. At 77 F. the air of a room contains water vapor at a partial 

 pressure of 20 mm. What is the percentage of humidity? 



4. What weight of water is contained in a cubic meter (1000 

 liters) of air saturated at 10 C.? 



5. What weight of carbon is contained in the total carbon 

 dioxide in the earth's atmosphere? 



6. Air at 18 has to be cooled to 14 before it deposits dew or 

 fog. What is the percentage humidity at 18? 



7. Why is the air nearest the ground heated (by the sun) to a 

 higher temperature than the upper air? 





