IN CHEMISTRY. 59 



23. What weight of Glauber salt can be formed from 100 

 Ibs. of oil of vitriol? * 



SO S : NaO.SOg : : 100 Ibs. : x. 



40 : 71 : : 100 Ibs. : x. 

 x = 177.5 Ibs. (NaO.S0 3 ). 



24. What weight of S is there in 10 grs. of sulphide of 

 hydrogen ? 



S : HS : : x : 10 grs. 



16 : 17 : : x : 10 grs. 



z = 9Vn grs. (S). 



25. How much O is required to change a Ib. of SO^ to 

 SOJ 



S0 2 : S0 3 : : 1 Ib. : x. 



32 : 40 : : 1 Ib. : x. 



x = 1 J /4 Ib. (SO 3 ). 



!V 4 lb. llb. = V 4 Ib. (O). 



26. How much phosphorus in 40 Ibs. of phosphate of limet 



(See page 245.) P : 3CaO.PO 8 : : <B : 40 Ibs. 



31 : 155 : : x : 40 Ibs. 

 x = 8 Ibs. (P). 



27. How much P in 40 Ibs. of the superphosphate of lime ? 



P : CaO.PO 5 : : x : 40 Ibs. 

 31 : 99 : : x : 40 Ibs. 

 x = 12 "/ Ibs. (P). 



28. How much phosphate of lime will an oz. of P make ? 



P : 3CaO.P0 6 :: loz. : x. 

 31 : 155 : : 1 oz. : x. 

 x = 5 oz. (3CaO.PO 6 ). 



29. How many Ibs. of HO in 186 Ibs. of SO^HO f 



8HO : S0 3 .3HO : : x : 186 Ibs. 

 27 : 67 : : x : 186 Ibs. 

 a; = 74V67 Ibs. (HO). 



* In this, as in the other problems, the HO contained in the acid and In 

 the salt is neglected, since it is a variable quantity, and the examples are 

 merely for practice. 



