Calculate the percentage composition of oxygen in lead nitrate [Pb(NO3)2].
(Pb = 207, N = 14, O = 16)
Molecular mass of [Pb(NO3)2] = [207 + 2{14 + (316)}] g = 331 g
Mass of oxygen in [Pb(NO3)2] = 96 g
Hence, percentage composition of oxygen in [Pb(NO3)2] is 29 %.