Question

.The displacement reaction
between iron (III) oxide and a
metal X is used for welding the
rail tracks. Here X is:
O
a. Copper granules
O b. Magnesium ribbon
O c. Sodium pellets
O d. Aluminium dust​

Answer 1

For welding railway tracks, we use a mixture of Iron oxide and Aluminium dust. This mixture is also known as Thermite. Aluminium being more reactive than Iron, can displace Iron from its oxide to give rise to aluminium oxide, Iron and evolution of heat takes place.

Reaction:

$\large{ \boxed{ \sf{Fe_2O_3 + 2Al \longrightarrow 2Fe + Al_2O_3 + Heat}}}$

So, Correct option is:

☑ $\large{ \pink{ \underline{ \underline{ \bf{ \purple{Alumimium \: dust \: (D)}}}}}}$

In metallurgy, we use carbon pure form, known as Coke but sometimes we use the help of displacement reactions. Highly reactive metals like Sodium, Aluminium and Calcium are used as Reducing agents.

➤ When Aluminium is used like in the Q., it is also known as Aluminothermy or Thermite process (Because mixture is known as Thermite).

Explore more !!

METALLURGY....

Not all metals are obtained directly from the nature, but pure metal is extracted from ore, this process is called Metallurgy. This involves many processes like:

• Crushing the ore into small pieces.
• Then, Concentrating the ore(ore-dressing).
• Then, there is extraction of metal from the made concentrated ore in step-2)
• Then, This is purified and refined to get the impurity free pure metal.

☃️ While in the third step, That is Extraction of metal from ore, it also includes two sub-steps for metals found in the middle of activity series:

• Conversion into metal oxide
• And then, Reduction of the metal oxide to metal.

➤ As in the question, Fe(Iron) is found in the middle of activity series, we follow the above two steps for its extraction from ore. This is also used in welding tracks.

━━━━━━━━━━━━━━━━━━━━