IN CHEMISTRY. 93 



(z). H,N : H 4 N,C1 : : x : 3 Ibs. 

 17 : 53.5 : : x : 3 Ibs. 

 53-5 *" = 5* Ibs. 



x = m lb. (H 3 N). 



(2). From the formulae it is seen that any amount of sal-ammoniac will 

 yield |5f its weight of ammonia: hence, 3 Ibs. will give 3 Ibs. x ||f = fgf 

 lb. (H,N). 



5. flow much H 2 O will be formed in the process'} 



By examining the reaction given in the Chemistry ', page 

 48, it will be seen that \ of the H in each molecule of 

 H 4 N,C1 goes to form H 2 O. Hence, find (i) how much 

 H there is in 3 Ibs. of sal-ammoniac, and (2) how much 

 H 2 O would be formed by J- that amount of H. 



(i) H 4 : H 4 N,C1 : : x : 3 Ibs. 

 4 : 53-5 : : * V 3 Ibs. 

 53.5 jr = 12 Ibs. 



x = T <& lb. (H). 



( 2 ) T %V lb. + 4 = T ^T lb. TT lb. x 9 * = T 5 V lb. (H a O). 



6. ^?z/ wwr/^ CaO will be needed? 



Find (i) how much O there is in -ffe lb. of H 2 O ; 

 and (2) how much CaO would be needed to furnish that 

 amount of O. 



(i) T S 5 V lb. x I * = T 5 8 7 - lb. ; hence, there are ^ r lb. of O in the water pro- 

 duced. 



(2) O : CaO : : T Vr lb. : x. 

 16 : 56 : : T 4 5 8 7 lb. : x. 

 16 x = -\ 9 oV 8 -- 



x - 1.57 + Ibs. (CaO). 



7. In separating N, how much air will be needed to fur- 

 nish a gallon of the gas ? 



About f of the atmosphere is N : hence, J of a gallon 

 of common air would be required to furnish one gallon 



of N. 



* See Chemistry \ page 24. 



