Răspuns:
C₄H₆- simbol butina
M=12*4+1*6=48+6=54g/mol
54g.............48g C.........6g H
100g..............xgC..........ygH
x=100*48/54=4800/54=88.88g %C
y=100*6/54=600/54=11.11 % H
