Question

Name the compound formed by heating iron filling with sulphur powder:

Answer 1

Hint:The heating of iron filings with sulphur powder is an exothermic reaction. In this reaction, the two solid particles of the element iron and sulphur are mixed and it is heated. This reaction is used to illustrate the differences between compounds and mixtures.

Complete step by step answer:
In this reaction, both the solid particles of iron and the sulphur are mixed and it is heated.
This reaction is carried out in an ignition tube.
This reaction is exothermic. That is the liberation of heat takes place due to this reaction.
The reaction between the iron filling and sulphur is used to demonstrate the differences between mixtures and compounds.
When the iron filling is heated with sulphur, a compound called iron sulphide is formed.
The reaction is shown below:
$Fe + S \to FeS$
The compound formed by heating iron filling with sulphur powder is iron sulphide.
Therefore the answer is iron sulphide, $FeS$.

Additional Information
As mentioned earlier this experiment illustrates the differences between mixtures and compounds.
When we mix the iron powder and sulphur powder, we get a mixture.
A mixture can be separated by physical means.
Using a magnet the iron powder in the mixture can be separated from the sulphur powder in the mixture.
But when we heat the mixture of iron filings and sulphur, the product we get is iron sulphide.
Iron sulphide is a compound. It is not a mixture.
Iron (II) sulphide formed is non-magnetic. It cannot be separated by physical means.
Thus mixtures can be separated by physical means but compounds cannot be separated by physical means.
Therefore this experiment illustrates differences between mixtures and compounds.


Note:
The compound formed by heating iron filings and sulphur is iron sulphide. When dilute $HCl$ is added to iron sulphide, hydrogen sulphide gas is evolved. The compound iron sulphide is black coloured. The mixture of iron filings and sulphur is heterogeneous whereas the compound iron sulphide formed by heating them is homogeneous.