56 AJfSWJSRS TO PRACTICAL QUESTIONS 



H = 1 = equivalent of given constituent. 

 HO = 9 = . " " compound. 



x = weight of given constituent. 

 50 Ibs. = " " compound. 



1 : 9 : : x : 50 Ibs. 

 aj = 5/9 Ibs. (H). 



More simply, i of water is H ; hence 

 50 Ibs. + 9 = 5 /9 Ibs. (H). 



9. How much saltpetre will be required to make 18 lot, 

 of aquafortis ? 



NO 5 = 54 = equivalent of given constituent. 

 KO.NO B = 101 = " " compound. 



18 Ibs. = weight of given constituent. 

 x = " " compound. 



54 : 101 : : 18 Ibs. : x. 

 x = 33 V 8 Ibs. (saltpetre). 



10. How much oil of vitriol will be required to decompose 6 

 Ibs. of saltpetre ? 



First find how much KO in 6 Ibs. of KO.NO 6 , next how 

 much KO.SO, that amount of KO will make, and lastly sub- 

 tract the KO from the KO. SO 3 , and the remainder will be the 

 SO,. In both cases we neglect the HO combined in the salts 

 and the acid. 



KO : KO.NO 5 : : x : 6 Ibs. 



47 : 101 : : x : 6 Ibs. 



'x = 2.79 Ibs. (KO). 



KO : KO.S0 3 : : 2.79 Ibs : x. 



47 : 87 : : 2.79 Ibs. : x. 



x = 5.16 Ibs. (KO.SO 8 ). 



6.16 IDS. (KO. S0 8 ) 2.79 Ibs. (KO) = 2.37 Ibs. (SO 8 ). 



II. How much HO will be decomposed by one drachm of 

 K, and how much KO will be formed? 



First find how much KO I dr. of K will form, then sub- 

 tract from the KO the drachm of K, and the remainder is the 

 0, which must be 5 of the water from which it is obtained. 



