IN POPULAR CHEMISTRY. 81 



37. How much CO 2 will be formed in the combustion 

 of 3O gm. of CO ? 



CO : CO 3 : : 30 gm. : x. 



f 28 : 44 : : 30 gm. : x. 



28 x = 1,320 gm. 



x = 47.14 gm. (CO 2 ). 



38. What tveight of CaCO s would be required to evolve 

 12 grams of CO 2 ? 



CO 2 : CaCO 3 : : 12 : x. 

 44 : 100 : : 12 : x. 

 x = 2?! 3 T grams. 



39. What would be the volume of these 12 grams of 

 CO 2 at 12 C. and 744 mm. ? 



The molecular weight of CO 2 [12 + 2(16)], is 44. Its density 

 is therefore 22. Under standard conditions 1 liter of H weighs 

 .0896 gm. ; therefore 1 liter of CO 2 weighs 22 x. 0896 gm., or 

 1.97 gm. The number of liters that would weigh 12 gm. is 



12 



hence : r7 r^, or 6.09 liters. At 12 C. and 744 mm. this volume 

 1.97 



would be expanded to 



Ar 285 760 _ no 

 V== 273 X ^4 x6m 

 V = 6.494 liters. 



40. Hoiv much C would be necessary to furnish CO 2 

 enough to fill a gas-holder 1O meters high and 4 meters in 

 diameter when the temperature is 25 C., and the barome- 

 ter stands 754 mm. ? 



First find the capacity of the gas-holder. The volume of a 

 cylinder is equal to its length multiplied by the area of its 

 cross action. In this case it is 10 x 3.1416 x(2) a , or 125.664 

 cubic meters. Since in a cubic meter there are 1,000 liters, this 

 volume is 125,664 liters, the temperature being 25 C., and the 

 pressure 754 mm. Reducing this to standard conditions, we 



070 7^4. 

 have V = 125,664 x x 



V = 114,810.5 liters. 



