Itf CHEMISTRY. 63 



46. How many Ibs. of HCl would be required to neutralize 

 sufficient carbonate of ammonia to form a 30 Ib. cake of sat- 

 ammoniac (NH V Cl) ? 



First find how much Cl there is in a 30 Ib. cake of sal- 

 ammoniac ; second, how much HCl would contain that amount 

 of CL 



Cl : NH 4 C1 : : x : 30 Ibs. 

 85.5 : 53.5 : : x : 30 Ibs. 



x = 19.9 Ibs. (Cl). 



Cl : HCl : : 19.9 Ibs. : x. 



35.5 : 36.5 : : 19.9 Ibs. : x. 



x = 20.4 Ibs. (HCl). 



47. How much S is there in a ton of plaster (gypsum) f 



S : CaO.SO, : : x : 2000 Ibs. 



16 : 68 : : x : 2000 Ibs. 



x = 470.58 Ibs. (S). 



48. How much aluminum is there in a ton of clay t 



2A1 : Al a O 3 .SiO 3 : : x : 2000 Ibs. 



27.4 : 81.4 : : x : 2000 Ibs. 



= 673.2 Ibs. (Al). 



49. How much K is there in 10 Ibs. of alum f 



K : (KO.S0 8 +A1 2 O,.3SO,+1HO) : x : 10 Ibs. 



39 : 474.4 : : x : 10 Ibs. 



x = .82 Ib. (K). 



50. How much white-lead (PbO.COJ could be made from 

 I Ib. of litharge 1 



Pb : PbO : : x : 1 Ib. 



103 : 111.6 : : x : 1 Ib. 



= .92 Ib. (Pb) in 1 Ib. of litharge. 



Pb : PbO.C0 2 : : .92 Ib. : x. 



103 : 133 : : .92 : x. 

 x = 1.1 Ib. (PbO.CO a ). 



51. How many Ibs. of C would be required to reduce 40 

 tons of brown hematite (-zFe^O^HO) ? 



In the intense heat of the furnace the 3 HO would be de- 

 composed, and so only sufficient C would be required to burn 



