Question

A student was given a mixture of sulphur and iron filings. He was told to heat it and observe it.What will be the colour of the compound formed?
A.The compound will be of Red colour
B.The compound will be of Black colour
C.The compound will be of Orange colour
D.The compound will be of Blue colour

Answer 1

Hint:When two compounds or elements are kept together and heated, they tend to react with each other to form a new compound. Here iron and sulphur, when heated, tend to react and undergo direct combination or synthesis reaction.

Complete answer:
Iron is a metal with symbol Fe. Atomic number of iron is twenty-six. It is an element of group eight and the first transition series. It is an element which is found in earth's crust. It is the fourth most common element that is found in earth's crust. It has two valances that are plus two \[\left( { + 2} \right)\] and plus three \[\left( { + 3} \right)\]. Iron fillings are small pieces of iron.
Sulphur is a non-metal of group 16 with atomic number 16. When the conditions are normal, sulphur atoms form a cyclic octatomic structure which contains eight atoms of sulphur.
When we heat sulphur and iron filings together, they form iron sulphide. It is usually black in colour.
Therefore, the observation made is that the colour of the compound formed will be black and it is iron sulphide.

Hence, the correct answer is option B.

Note:
Uses of iron sulphide:
-It is used in alloy of iron and stainless steel.
-It is used in the steel industry as a re-sulphurisation agent in the manufacturing of alloy and carbon free cutting steels.
-Iron sulphide is used in production of malleable iron.