Show that the data given below is in agreement with the law of constant composition
`{:("Exp. No.","Mass of iron","Mass of iron oxide"),("(i)","2.7812 g","3.9756 g"),("(ii)","3.0499 g","4.3596 g"),("(iii)","4.4913 g","6.4202 g"):}`

Explanation

Experiement No. (i)
Mass of iron = 2.7812 g , Mass of iron oxide = 3.9756 g
Percentage of iron `= ((2.7812g))/((3.9756g))xx100=70%`
Percentage of oxygen `= 100 - 70 = 30 %`
Experiment No. (ii)
Mass of iron = 3.0499 , Mass of iron oxide = 4.3596 g
Percentage of iron `= ((3.0499))/((4.3596g))xx100=70%`
Percentage of oxygen `= 100-70=30%`
Experiment No. (iii)
Mass of iron = 4.4913 g , Mass iron oxide = 6.4202 g
Percentage of iron `= ((4.4913g))/((6.42402g))xx100=70%`
Percentage of oxygen `= 100 - 70 = 30 %`
Since the ratio by weights of iron and oxygen in the three oxides is the same, the data is according to Law of constant Composition.