CBSE Class 9 Answered

Mass of the yellow oxide of lead = 3.45 g

Loss in mass due to reduction = 0.24 g

Mass of lead in I oxide = 3.45-0.24 = 3.21 g

Mass of Oxygen in I oxide = 0.24 g

Mass of the brown oxide of lead = 1.227 g

Loss in mass due to reduction = 0.16 g

Mass of lead in I oxide = 1.227 - 0.16 = 1.07 g

Mass of Oxygen in I oxide = 0.16 g

In I oxide, the amount of Pb that combines with 1 part by mass of O = (3.21/0.24) = 13.37

In II oxide, the amount of Pb that combines with 1 part by mass of O = (1.07/0.16) = 6.69

Ratio of mass of Pb in I oxide : mass of Pb in II oxide = 13.37 : 6.69 = 1.998 : 1 = 2 : 1. 

Therefore, it can be concluded that, the data is in agreement with law of multiple proportion.