9 ANSWERS TO PRACTICAL QUESTIONS 



The rate of change varies with the amount of oxida- 

 tion, and that depends on the use of the organ. The 

 right arm of the blacksmith must be transformed much 

 more rapidly than the left. 



15. What objects would escape combustion ? 



Burnt bodies, i. e., those which are already combined 

 with oxygen. 



1 6. How much oxygen can be obtained from 6 oz. of 

 KClOo ? 



: , : KC10 3 : : x : 6 oz. 



48 : 122.5 : x ' 6 oz. 



122.5 x 288 oz. 



x = 2.35 oz. (O). 

 Or (see Chemistry, page 28), & x 6 oz. = 2 ? s oz. (O). 



17. How much KC1O 3 would be needed to produce 2 

 Ibs. 0/O? 



O, : KC1O 3 : : 2 Ibs. : x. 



48 : 122.5 : : 2 ^bs. : jr. 



48 x = 245 Ibs. 



x = Si V Ibs. (KC1O,). 



1 8. How much KC1 would be formed in preparing i 

 Ib. o/O 



(See Chemistry, page 28, diagram.) 



If i Ib. is sW of a compound, what are ^f ? 

 Ans. -V<f Ibs. = ifc| Ibs. (KC1). 



19. Name a substance from which the O can be set free 

 by the stroke of a hammer. 



Potassium chlorate. 



20. Name one from which it is liberated with great 

 difficulty. 



Sand, carbonic anhydride. (See C/tem,, p. 98, note.) 



