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2014-10-12T10:17:07+03:00
Aflam masa molara (miu) C7H8O= 12*7+8*1+16= 108g/mol 
masa molara de C7 = 12*7=84 g/mol
masa molara de H8= 8*1=8 g/mol
masa molara de O = 16*1=16 g/mol
108gC7H8O......84gC.......8gH......16gO
100gSubstanta... XgC.......YgH......ZgO
XgC= 100*84/108= 8400/108= 77,7gC
YgH= 100*8/108= 800/108=7,40 gH
ZgO= 100*16/108= 1600/108=14,81gO
Formula procentuala este : 77,7%C , 7,40%H , 14,81%O 
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