Empirical formula x n = Molecular formula
so, empirical formula mass x n = molecular formula mass
Mass of Si = 28.0855 and H = 1.008
(28.0855 g + 3 x 1.008g) x n = 62 g
31.1095 x n = 62
31.1095 is equal to 31 approximately
n = 62/31 = 2
So, 2 x SiH₃ = Si₂H₆
Si₂H₆ is the molecular formula of the compound.
