Question

In aluminothermic process, Al acts as a:
A. Flux
B. Oxidising agent
C. Reducing agent
D. Solder

Answer 1

Hint – We will start this question by writing some important details about aluminium and then we will discuss the aluminothermic process, aluminothermic reaction and its uses in industry and in metallurgy and then the role of aluminium in aluminothermic process.

Step -By-Step solution:
Aluminium is a member of group 13 of p-block in the periodic table. Its electronic configuration is $1{s^2}2{s^2}2{p^6}3{s^2}3{p^1}$, also written as $\left[ {Ne} \right]3{s^2}3{p^1}$. Its symbol is Al, atomic number is 13 and atomic mass is 26.98u or 27u.

Aluminothermic process is the process used for the production of alloys of iron. These reactions are exothermic in nature which means that heat is released in these reactions.

Aluminothermic reactions have been used to weld rail tracks on-site, useful for complex installation or local repair that cannot be done using continuously welded rail. Another common use of this process is the welding of copper cables (wire) for use in direct burial application.

Aluminothermic processes are very useful in metallurgy in the conversion of some metal oxides to their respective metals. As some metal oxides cannot be reduced satisfactorily by carbon. So for them, aluminium which is a more reactive metal is used. Due to strong affinity for aluminum, it can reduce certain metal oxides such as $F{e_2}{O_3}$and $C{r_2}{O_3}$to corresponding metals.

In the aluminothermic process, aluminium is used as a reducing agent to reduce other, metal oxides to their respective metals.
For example:
In the reaction of aluminium with iron(III) oxide, which is a type of aluminothermic reaction, the oxidation state of aluminium is increased. Hence, it is considered as a reducing agent because it undergoes oxidation process. The reaction follows:
$F{e_2}{O_3} + 2Al \to 2Fe + A{l_2}{O_3}$
Oxidation state of Aluminium on the reactant side is 0.
Oxidation state of Aluminium on the product side is +3.

From the above discussion it is clear that aluminium is used as a reducing agent in aluminothermic processes.
Hence, option C is the right answer.

Note – Aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent, at high temperature. The process is industrially useful for production of alloys of iron. The process is called an alumino-thermic process or thermic process.