Question

The reducing agent in the thermite process is:
(A) Cu
(B) Al
(C) Zn
(D) Mn

Answer 1

Hint: Thermite process is an exothermic reaction which liberates a large amount of heat. Practically, this method can be used to reduce all the metallic oxides, with oxide of magnesium being the only exception.

Complete step by step solution:
The thermite process was discovered by a German chemist named Hans Goldschmidt (1861-1923) in 1893. Goldschmidt was only interested in extracting very pure metals, but he soon came to know its value in welding, a process known as Thermite welding. Alumino thermite is a process of extracting metals by reduction of a metal oxide to form metal using aluminium powder, the aluminium acts as a reducing agent.
Here are a few examples of Alumino thermite process:
-Reduction of ferrous oxide to ferrous metal
Iron (III) oxide is mixed with aluminium powder and is ignited with a burning magnesium ribbon. Aluminium reduces iron oxide to produce a molten iron metal with the evolution of heat. The chemical reaction is given as:
\[F{{e}_{2}}{{O}_{3}}+2Al\to 2Fe+A{{l}_{2}}{{O}_{3}}+Heat\]
-${C{r_2}{O_3}}$ is reduced to chromium metal.
A mixture of Chromic oxide and powdered aluminium in the ratio of 3:1 and is ignited by a piece of magnesium ribbon. A large amount of heat is liberated during this process and chromic oxide is reduced to chromium. The chemical reaction is given as:
\[C{{r}_{2}}{{O}_{3}}+2Al\to 2Cr+A{{l}_{2}}{{O}_{3}}+Heat\]
We can understand from the above discussion that we use aluminium as a reducing agent in the thermite process.

Therefore, the correct answer is option (B) aluminium.

Note: This reduction property of aluminium is used in thermite welding for joining the broken pieces of heavy iron objects like girders, railway tracks or cracked machine parts of various machinery