While conducting experiment on decomposition reaction 2g of ferrous sulphate crystals are heated in a boiling tube.
Answers
Answer:
Procedure:
Real Lab Procedure:
Take about 2g of ferrous sulphate crystals in a dry boiling tube and note the colour of the crystals.
Hold the boiling tube with a test tube holder and heat the boiling tube over a burner's flame.
Smell the gas being emitted.
Observe the colour of the crystals after heating.
Observations:
*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.
Inference: 2Feso4(s)----------------->Fe2O3(s) + So2(g) + So3(g)
*Ferrous sulphate crystals contain water molecules (FeSO4. 7H2O). On heating, ferrous sulphate crystals lose water and anhydrous ferrous sulphate (FeSO4) is formed. So their colour changes from light green to white.
*On further heating, anhydrous ferrous sulphate decomposes to form ferric oxide (Fe2O3), sulphur dioxide (SO2) and sulphur trioxide (SO3). So, the gas emitted smells like burning sulphur.
*In this reaction, the single reactant FeSO4 decomposes to form three different products. So, the reaction is a decomposition reaction.
Precautions:
1.Do not point the mouth of the boiling tube at your neighbours or yourself.
2.Waft gases emitted from ferrous sulphate on heating gently towards your nose holding the test tube at a distance. The gases SO2 and SO3 are very harmful, so do not take a deep breath when smelling the odour of the gases.
3.Always use a test tube holder while heating the test tube.