Question

The following data were obtained for three oxides of lead
(i) 1.77 g of red oxide contains 1.61 g of lead
(ii) 6.90 g of the yellow oxide contains 6.42 g of lead
(iii) 1.195 g of brown oxide contains 1.035 of lead.
Justify that the data is in agreement with the law of multiple proportions.

Answer 1

(i) 1.61 g of lead are combined with oxygen `= 1.77 - 1.61 = 0.16` g
1.0 g of lead are combined with oxygen `= (0.16)/(1.61) g = 0.099 g`
(ii) 6.42 g of lead are combined with oxygen `= 6.9 - 6.49 = 0.48 g`
1.0 g of lead are combined with oxygen `= (0.48)/(6.42) g = 0.075 g`
(iii) 1.035 g of lead are combined with oxygen `= 1.195 - 1.035 = 0.16 g`
1.0 g of lead are combined with oxygen `= (0.16)/(1.035)g = 0.1546 g`
The ratio by mass of oxygen combining with 1.0 gram of lead in the three oxides is :
`0.099 : 0.075 : 0.1546 or 4: 3: 6`
Since it is a simple whole number ratio, if illustrates the law of multiple proportions.