0.79 g of iron unite directly with 0.4 g sulphur to form ferrous sulphate. If 2.8 g of iron are dissolved in dilute HCl and excess of sodium sulphide solution is added, 4.4 g iron sulphite is precipitated. Show that the data is according to Law of constant composition.

0.79 g of iron unite directly with 0.4 g sulphur to form ferrous sulph

1.	0.79 g of iron unite directly with 0.4 g sulphur to form ferrous sulphate. If 2.8 g of iron are dissolved in dilute HCl and excess of sodium sulphide solution is added, 4.4 g iron sulphite is precipitated. Show that the data is according to Law of constant composition.
Answer» Solution :In the first sample : Ratio by mass of IRON and sulphur is : 0.7 : 0.4 or 7 : 4 In the second sample Mass of iron dissolved = 2.8 G Mass of iron sulphide formed = 4.4 g Mass of sulphuric reacted `= (4.4 - 2.8) = 1.6 g` Ratio of mass of iron and sulphur is : 2.8 : 1.6 or 7 : 4 Since the ratio by mass of Fe and S in the TWO samples is the same, this VERIFIES the Law of constant composition.