1 76 



ELEMENTARY LESSONS ON [CHAP. in. 



" equivalent" 1 of copper is 31-5; multiplying this by 

 0000105 we get as the electro -chemical equivalent of 

 copper the value -00033075 (grammes). 



212. TABLE OF ELECTRO-CHEMICAL EQUIVALENTS, ETC. 



1 The chemical " eqTiivalent" must not be confounded with the "atomic 

 weight." The atomic weight of copper is 63, that is to say, its atoms are 63 

 times as heavy as atoms of hydrogen. But in chemical combinations one 

 atom of copper replaces, or is "worth," two atoms of hydrogen ; hence the 

 weight of copper equivalent to i of hydrogen is 6 -/ = 31 J. In all cases the 



atomic weight. 



chemical "equivalent is the quotient V alenc ^ >ne a ^ ove Table 



gives full statistical information. 



