Question 15 Marks
a. What is thermit process? Where is this process used? Write balanced chemical equation for the reaction involved.
b. Where does the metal aluminium, used in the process, occurs in the reactivity series of metals?
c. Name the substances that are getting oxidised and reduced in the process.
b. Where does the metal aluminium, used in the process, occurs in the reactivity series of metals?
c. Name the substances that are getting oxidised and reduced in the process.
Answer
View full question & answer→a. The thermite process, also known as the thermite reaction or thermit process, is a type of exothermic reaction in which a metal oxide reacts with a more reactive metal to produce molten metal and a metal oxide as the byproduct. This reaction is highly exothermic and is often used for welding or in pyrotechnic displays. In thermite reaction, iron oxide reacts with aluminium to produce molten iron.
The following reaction of iron oxide with aluminium as:
$\mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s})+2 \mathrm{Al}(\mathrm{s}) \longrightarrow 2 \mathrm{Fe}(\mathrm{l})+\mathrm{Al}_{2} \mathrm{O}_{3}(\mathrm{~s})+$ heat
This is used to join railway tracks or cracked machine parts because the amount of heat evolved is so large that the metal is produced in the molten state.
b. The reactivity series of metals as: $\mathrm{K}>\mathrm{Na}>\mathrm{Ca}>\mathrm{Mg}>\mathrm{Al}>\mathrm{C}>\mathrm{Zn}>\mathrm{Fe}>\mathrm{Sn}>\mathrm{Pb}$As aluminium is more reactive than iron so it is placed above iron in the reactivity series.
c. In this process, aluminium is getting oxidised to aluminium oxide and iron oxide is getting reduced to iron.
The following reaction of iron oxide with aluminium as:
$\mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s})+2 \mathrm{Al}(\mathrm{s}) \longrightarrow 2 \mathrm{Fe}(\mathrm{l})+\mathrm{Al}_{2} \mathrm{O}_{3}(\mathrm{~s})+$ heat
This is used to join railway tracks or cracked machine parts because the amount of heat evolved is so large that the metal is produced in the molten state.
b. The reactivity series of metals as: $\mathrm{K}>\mathrm{Na}>\mathrm{Ca}>\mathrm{Mg}>\mathrm{Al}>\mathrm{C}>\mathrm{Zn}>\mathrm{Fe}>\mathrm{Sn}>\mathrm{Pb}$As aluminium is more reactive than iron so it is placed above iron in the reactivity series.
c. In this process, aluminium is getting oxidised to aluminium oxide and iron oxide is getting reduced to iron.