ANSWERS 



TO THE 



PRACTICAL QUESTIONS AND PROBLEMS 



IN THE 



FOURTEEN WEEKS IN CHEMISTRY, 



REVISED EDITION, 

 WITH NEW NOMENCLATURE. 



[The large figures refer to the page of the Chemistry^ and the small ones 

 to the number of the Question^ 



24. i. In a 2$-lb. sack of common salt, how many 

 pounds of the metal sodium ? 



Na = 23 = atomic weight of the given element. 

 NaCl = 58.5 = molecular weight of the compound. 



x = weight of the given element. 

 25 Ibs. = " " compound. 



Na : NaCl : : x : 25 Ibs. 

 2 3 : 58.5 : : x : 25 Ibs. 

 58.5 x = 575 Ibs. 



x = 9r V T Ibs. (Na). 



2, In 14 Ibs. of iron rust (Fe 2 O 3 ), how much O? 



O s = 48 = atomic weight of the given element. 

 Fe a O 3 = 160 = molecular weight of the compound. 



x = weight of the given element. 

 14 Ibs. = w u compound. 



O 8 : Fe a O s : : x : 14 Ibs. 

 48 : 160 : : x : 14 Ibs. 

 160 x 672 Ibs. 

 x = 4 Ibs. (O). 



