Question

How do you identify the gases evolved in ferrors sulphate crystals

Answer 1

When the crystals are heated, they disintegrate first and form an hydrous Ferrous Sulphate. A change of colour is observed from green to white. It further decomposes to give gaseous products like Sulphur Dioxide and Sulphur Trioxide. These gases are extremely pungent in smell and suffocate

Answer 2

Answer:

When ferrous sulphate crystals are heated , it decomposes to form ferric oxide (Fe2O3) , sulphur dioxide (SO2) and sulphur trioxide (SO3).

The process is a Thermal Decomposition process as heat is involved in this process.

2FeSO4 → Fe2O3 + 4SO2 + SO2

The observations of this reactions are:

• The ferrous sulphate crystals are light green in colour.

• The gas emitted has the characteristic odour of burning sulphur.

• On heating, the colour changes from light green to white.

• On further heating, the white substance changes to dark brown solid.