Chemistry and Chemical Reactivity (9th Edition)

Empirical formula $CH$ Molecular formula: $C_2H_2$
Atomic weights (g/mol): $C: 12.011,\ H: 1.008$ In 100.0 g: C: $92.26\ g \div 12.011 = 7.68\ mol$ H: $7.74\ g\div 1.008 = 7.68\ mol$ Normalizing by the smallest amount of moles: C,H: $7.68/7.68 = 1.0$ Empirical formula $CH$ Empirical formula's molar mass: $M_u=13.02\ g/mol$ $M/M_u=2.0$ Molecular formula: $C_2H_2$