100 g aminoacid...40.45 g C..7.86 g H....15.73 g N....35.96 g O
M g aminoacid.......X g C...........Y g H.................14g N..... ..z g O
M=14*100/15.73=89 g/mol
x=40.45*14/15.73=36 g C; n=m/A=36/12=3 atomi de C
y=7.86*14/15.73=7 g H; n=7/1=7 atomi de H
z=35.96*14/15.7= 32 g O n=32/16=2 atomi de O
Formula moleculara: C₃H₇NO₂